light travelling through eye

How the Eyes Work

All the different parts of your eyes work together to help you see. First, light passes through the cornea (the clear front layer of the eye). The cornea is shaped like a dome and bends light to help the eye focus. Some of this light enters the eye through an opening called the pupil (PYOO-pul). The iris (the colored part of the eye) controls how much light the pupil lets in.

Next, light passes through the lens (a clear inner part of the eye). The lens works together with the cornea to focus light correctly on the retina. When light hits the  retina  (a light-sensitive layer of tissue at the back of the eye), special cells called photoreceptors turn the light into electrical signals.

These electrical signals travel from the retina through the  optic   nerve  to the brain. Then the brain turns the signals into the images you see. Your eyes also need tears to work correctly.

Last updated: April 20, 2022

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How the Human Eye Works – Step by Step

Humans eyes work much like cameras. Here is a simple step-by-step explanation of how the human eye works and a look at the structure and function of the parts of the eye.

Parts of the Eye and Their Functions

To understand how the human eye works, you need to know the names and functions of its structures.

• Cornea : The cornea is the transparent outer surface of the eye. Because the eyeball is round, the cornea acts as a lens that bends or refracts light. Corneal cells regenerate quickly, because the cornea is exposed to the environment. But, the layer is thin enough to allow oxygen into the deeper structures.
• Aqueous Humor : The aqueous humor is the fluid layer below the cornea. It has a composition similar to human plasma. The aqueous human shapes the cornea and nourishes the cells of the eye.
• Iris and Pupil : Light passes through the cornea and aqueous humor through a hole called the pupil. The iris is a contractile ring that determines eye color and controls the size of the pupil. The iris dilates (opens) the pupil in low light so more light enters the eye and constricts in bright light.
• Lens : While the cornea initially focuses light, the lens makes it so you can change focus between near and distant objects. Ciliary muscles around the lens contract to thicken the lens to focus on near objects. The muscles relax to flatten the lens to focus on distant objects.
• Vitreous Humor : The vitreous humor is a transparent gel that fills the eye. It supports the shape of the eye and provides enough distance so that the lens can focus.
• Retina : The retina is the coating on the inside of the back of the eye. It contains two types of cells. Rods detect light and help form images in dim light. Cones detect colors. There are three types of cones. They are called red, green, and blue cones, but they actually detect a range of wavelengths of light and not just the colors for which they are named.
• Fovea : The fovea is the circle of cells on the retina responsible for clear focus. This region is rich with cones, so it allows sharp color vision. Rods outside the fovea are largely responsible for peripheral vision.
• Optic Nerve : Light striking a rod or cone produces an electrochemical signal. The cells transmit this signal through the optic nerve to the brain.
• Brain : The visual cortex of the brain receives nerve impulses from both eyes and compares them to construct a three-dimensional image. Because the eye is like a camera, the true image formed on the retina is inverted (upside down). The brain automatically rights the image.

How the Human Eye Works

Now that you know the names of the parts of the eye, it’s easy to follow the steps leading to vision.

• Cornea : Light enters the eye through the cornea. Because of the shape of the cornea, it exits pre-focused.
• Aqueous Humor/Pupil : From the cornea, light passes through the aqueous humor and through the pupil.
• Lens : From here, light strikes the lens. The lens further focuses light, depending on whether you’re looking at a near or distant object. Light exits the lens and passes through the vitreous humor.
• Vitreous Humor : Ideally, the vitreous humor is clear and allows light to travel unimpeded to the retina.
• Retina : Light reaches the retina, activating rods and cones to generate electrical impulses that code for an inverted image.
• Optic Nerve : Signals from the rods and cones travel through the optic nerve to the brain.
• Brain : The brain compares left/right vision to add depth and make the image three-dimensional. It also flips the image so it appears right-side up.

Common Eye Problems

The most common eye problems are myopia (nearsightedness), hyperopia (farsightedness), and astigmatism. These conditions affect vision, but the eyes may be perfectly healthy.

• Myopia : Nearsightedness occurs when the focal point of the eye is in front of the retina. In other words, the eye is narrow rather than spherical.
• Hyperopia : Farsightedness occurs when the focal point of the eye is past the retina. In other words, the eye is slightly flattened rather than spherical.
• Presbyopia : Presbyopia is age-related farsightedness. It’s caused by stiffening of the eye’s lens over time. Presbyopia often improves myopia.
• Astigmatism : Astigmatism occurs when the eye curvature isn’t perfectly spherical. This makes light focus unevenly from one part of the eye to another.

Other common eye problems include glaucoma, cataracts, and macular degeneration. These conditions can lead to blindness.

• Cataracts : Cataracts are clouding and hardening of the lens.
• Macular Degeneration : Macular degeneration is progressive degeneration of the retina.
• Glaucoma : Glaucoma is increased fluid pressure within the eye. This can damage the optic nerve.

Interesting Eye Facts

Here are some fun and interesting eye facts you may not know:

• Babies are born with full-sized eyes. Eye size remains the same from birth until death.
• Blind people with eyes may still be able to sense light and dark . This is because there are cells in the eyes that detect light, but aren’t involved in image formation.
• Each eye has a blind spot where the eye attaches to the optic nerve. If you close one eye, you can find the blind spot. Normally, the second eye compensates and fills in the hole in your vision.
• The reason total eye transplants aren’t possible is because it’s presently too difficult to make the million-plus connections in the optic nerve.
• Humans don’t ordinarily see ultraviolet light , but the retina can detect it. The lens absorbs UV light before it reaches the retina, presumably to protect it from the high energy light capable of damaging rods and cones. However, people with artificial lenses report seeing ultraviolet.
• Blue eyes don’t contain any blue pigment. Instead, they lack pigment found in other eye colors. Rayleigh scattering of light causes the blue color in the same way as it makes the sky appear blue .
• Eye color can change over time. Usually, color change occurs from hormonal changes or chemical reactions from medications.
• Bito, L. Z.; Matheny, A.; Cruickshanks, K. J.; Nondahl, D. M.; Carino, O. B. (1997). “Eye Color Changes Past Early Childhood”.  Archives of Ophthalmology .  115  (5): 659–63. 
• Goldsmith, T. H. (1990). “Optimization, Constraint, and History in the Evolution of Eyes”.  The Quarterly Review of Biology .  65 (3): 281–322.

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 How Does the Eye Work?

Approximately 80 percent of everything we learn comes through our eyes — the question is, how?

The eye contains over two million working parts and is considered the second most complex organ in the body— the most complex is the brain. 

The inner structures of the eye all work together to produce an image that your brain can understand.

In order to produce a clear image, the eyes must complete a five step process:

Step 1: Light enters the eye through the cornea

When we look at an object, the light that is reflected off of the object enters the eye through the clear front layer of the eye, called the cornea . The cornea bends the light before it passes through a watery substance that fills the area behind the cornea, called the aqueous humor .

Step 2: The pupil adjusts in response to the light

The light continues to travel through the black opening in the center of the iris, called the pupil . The iris is the colorful part of your eye that gives it its blue, green, hazel, brown or dark appearance.

The pupil then automatically gets bigger or smaller, depending on the intensity of the light.

How does the pupil expand and contract?

The iris is actually made up of muscles that expand and contract to control the pupil and adjust its size. So when you see your pupil getting bigger or smaller, it is really the iris that is controlling the pupil opening in response to the intensity of light entering the eye.

Step 3: The lens focuses the light onto the retina

The light passes through the pupil to the lens behind it. The lens adjusts its shape to bend and focus the light a second time, to ensure that you have a clear image of what you are looking at.

At this point, the light has been bent twice— as it moved from the cornea through the lens, and then from the lens to the retina. This “double bending” has actually flipped the image upside down.

If you suspect you have blurry vision or an eye condition, contact an eye doctor  near you, who can diagnose and treat the condition.

SEE RELATED: Eye Anatomy: The Front of the Eye

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Step 4: the light is focused onto the retina.

The light then passes from the lens to the back of the eye which is filled with a clear, gelatinous substance called the vitreous until it reaches the retina , the light-sensitive layer at the back of the eye.

The light is then focused throughout the retina which contains nerves called photoreceptors . The photoreceptors are made up of rods and cones, and are responsible for transforming the light rays into electrical impulses. While the light is focused throughout the retina, most of the light entering the eye is focused onto the focal point on the retina, known as the macula .

Step 5: The optic nerve transmits visual information to the brain 

The nerves of the retina collect all of the electrical impulses, which then travel through the optic nerve at the very back of the eye up to the occipital lobe in the back of the brain .  

At this point, The light then passes from the lens to the back of the eye which is filled with a clear, gelatinous substance called the vitreous until it reaches the retina , the light-sensitive layer at the back of the eye.

The eye-brain connection

Vision is dependent on the connections between the eyes and the brain.

The light that enters the eye is required to go through a specific process in order to focus properly on the retina.

If the connections between the eye and brain are not well developed, the visual information that is sent to the brain will not be interpreted properly, and the image will be difficult to see.

The eye in its perfection

The process of seeing is dependent on the perfection of the eye and all of its components, including:

• Eyeball shape
• Corneal shape and integrity
• Lens clarity and curvature
• Retinal health

If any of these components do not function properly, or are irregularly shaped, vision problems can occur— most commonly, blurry vision will develop .

When this happens, corrective lenses in the form of eyeglasses or contact lenses are prescribed to help the light focus accurately onto the retina and enable clear vision.

Parts of the eye

Cornea: The clear dome-like structure that covers the front of the eye and is responsible for bending light as it enters the eye.

Pupil: The dark opening in the center of the eye that opens and closes in response to light intensity.

Iris: The colored part of the eye that is made up of muscles that control the pupil— contracting the pupil in bright light and expanding the pupil in low light.

Sclera: The white part of the eye that surrounds the iris. This structure is made up of fibrous tissue that protects the inner structures of the eye.

Lens: Located behind the pupil, this transparent structure focuses light onto the retina.

Ciliary body: Located behind the iris, this structure contains a muscle that helps to focus the lens.

Vitreous humor: The clear jelly-like substance that fills the central cavity of the eye.

Retina: The light-sensitive membrane that lines the back of the eye; responsible for transforming light signals into electrical impulses to be sent through the optic nerve to the brain.

Rods and Cones: Photoreceptors located in the retina, responsible for processing light signals. Rods allow you to see shapes, while cones allow you to see colors.

Macula: The center of the retina responsible for central vision, and vision for fine details.

Optic nerve: A bundle of nerve fibers that contains more than one million nerve cells. Located in the back of the eye, this nerve is responsible for carrying visual information from the retina to the brain.

LEARN MORE:    Guide to Eye Health

The eye is a fascinating part of your body, and the second most complex organ, after the brain .

If you notice any changes to your vision, make an appointment for an eye examination . Your eye doctor will assess your eye health and vision and provide various options to keep you seeing clearly.

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Science News Explores

Explainer: how our eyes make sense of light.

Special cells send data describing a scene into the brain, which interprets it

What we see of the eyes from the outside offers few clues to the light-interpreting operations at work inside.

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By Bethany Brookshire and Tina Hesman Saey

July 16, 2020 at 6:30 am

How do your eyes work? It’s far more than just forming a tiny picture in your eye. There’s also color and motion. It takes many cells — and finally the brain — to make sense of it all.

As light enters our eyes, it first heads through a tough outer tissue called the cornea. This protects the delicate inner eye from everything the world might throw at it. Light passes right through the cornea and into a transparent, flexible tissue called the lens. This lens focuses the light, sending it through the liquid-filled globe of the eyeball to the back interior wall of the eye.  

The tissue there, known as the retina, contains millions of light-sensitive cells. They are especially concentrated in an area called the fovea (FOH-vee-ah). This densely packed set of cells gives us the clearest picture of our world. When the eye focuses on an object, it directs the light bouncing off the object directly onto the fovea to get the best image. In fact, when the eye focuses on something, that’s called foveating (FOH-vee-ayt-ing).

The light-sensing cells on the retina are known as photoreceptors. Two important types are rods and cones. Each human retina (and you have two, one in each eye) contains 125 million rods and about 6 million cones. This is 70 percent of all the sensory receptors in your entire body — for touch, taste smell, hearing and sight all put together. That’s how important vision is to us.  

I’ll take a cone, please

Each rod or cone cell at the back of the eye has a stack of discs inside, The discs contain a pigment molecule. It’s bound to a protein called an opsin. Rods and cones each have a different opsin.

Cones have a pigment-protein pair called photopsin (Foh-TOP-sin). It comes in three different types, and each cone has just one type. They come in red, green or blue — the colors that each cone type is best at absorbing. Cones respond to light that has passed through the lens and onto the fovea. As each cone absorbs its color of light, it produces an electrical signal. These signals travel to the brain, filling our worlds with color.

In September 2016, a vision researcher at the University of Washington in Seattle discovered some cones also sense white light . But only white light. That was a big surprise, Ramkumar Sabesan said at the time.

In fact, he and his colleagues found, so-called red and green cone cells each come in two types. One transmits white light, the other relays color. Especially surprising, most of these cones are the white type. Out of 167 red cones tested, 119 signaled white. Of 98 green cones tested, 77 reported white light. (The team didn’t test white sensitivity among the retina’s few blue cones.)

White-sensing cells also detect black (which is the absence of white). The data they relay create a sharp black-and-white picture of someone’s surroundings. These provide a crisp edge to visual details. Red- and green-signaling cells fill in the lines with blurrier chunks of color. The process, says Sabesan, works much like filling in a coloring book or adding color to a black-and-white film.

Red, green, blue, black and white. These five colors end up making every single color that we see. Cone cells are especially concentrated in the fovea, and work only in bright light. At night, you need your rods.

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Rods are on the dark side

The retina’s rod cells aren’t part of the cone coloring system. They work when light levels are low. Instead of photopsins, rods have a different pigment-protein pair: rhodopsin (Roh-DOP-sin). Rods produce images only in shades of grey. But they are much more sensitive to light than cones are. They are so sensitive that a rod cell can detect a single photon of light — the smallest possible particle .

In the dark, we rely on our rods. But light inactivates these cells. It stimulates them so much that they become unresponsive. That’s all right, cones are there to take over. They require much more light to function. So we rely on cones in the light.

When they detect certain wavelengths of visible light, the photoreceptors trigger electrical signals. Rods and cones will send these signals through nerves that reach into the brain. They head for the occipital (Awe-SIP-ih-tal) cortex, right up against the back of the skull. There, the brain interprets these signals to make sense of what we’re looking at.

The retina also is home to another type of light-sensitive cell. These melanopsin ganglion (MEH-lah-NOP-sin GANG-lee-un) cells don’t send signals to the occipital cortex. Instead, they report the presence of light to the olivary pretectal nucleus (OH-liv-airy Pree-TEK-tahl NEW-klee-us). This is a tiny spot in the middle of the base of the brain. The signals that melanopsin ganglion cells send here help regulate the body’s master biological clock . They also send signals that control the size of the pupil (which controls how much light gets into the eye in the first place).

Light signals sent to this master body clock tell you when to be sleepy and when to be alert. But not just any light will do. This clock can distinguish between different colors of light. Blue works best to stimulate the body clock. Sunlight is an excellent source of blue light. Although it looks white, sunlight actually is a mix of many colors, including blue. This might explain why stepping outside on a bright sunny day helps clear the fog from your head .

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• How Does The Human Eye Work?
• About Keratoconus Eye Disease

To understand Keratoconus, we must first understand how the eye enables us to see, and what role the cornea plays in this process.

Light rays enter the eye through the cornea, the clear front “window” of the eye. The cornea’s refractive power bends the light rays in such a way that they pass freely through the pupil the opening in the center of the iris through which light enters the eye.

The iris works like a shutter in a camera. It has the ability to enlarge and shrink, depending on how much light is entering the eye.

After passing through the iris, the light rays pass thru the eye’s natural crystalline lens. This clear, flexible structure works like the lens in a camera, shortening and lengthening its width in order to focus light rays properly.

Light rays pass through a dense, transparent gel-like substance, called the vitreous that fills the globe of the eyeball and helps the eye hold its spherical shape.

In a normal eye, the light rays come to a sharp focusing point on the retina. The retina functions much like the film in a camera. It is responsible for capturing all of the light rays, processing them into light impulses through millions of tiny nerve endings, then sending these light impulses through over a million nerve fibers to the optic nerve.

Because the keratoconus cornea is irregular and cone shaped, light rays enter the eye at different angles, and do not focus on one point the retina, but on many different points causing a blurred, distorted image.

In summary, the cornea is the clear, transparent front covering which admits light and begins the refractive process. It also keeps foreign particles from entering the eye.

The pupil is an adjustable opening that controls the intensity of light permitted to strike the lens. The lens focuses light through the vitreous humor, a clear gel-like substance that fills the back of the eye and supports the retina.

The retina receives the image that the cornea focuses through the eye’s internal lens and transforms this image into electrical impulses that are carried by the optic nerve to the brain. We can tolerate very large scars on our bodies with no concern except for our vanity. This is not so in the cornea. Even a minor scar or irregularity in the shape can impair vision. No matter how well the rest of the eye is functioning, if the cornea is scarred, clouded or distorted, vision will be affected.

In keratoconus, the irregular shape of the cornea does not allow it to do its job correctly, leading to distortion of the image it passed to the retina and transmitted to the brain.

The eye is enclosed by a tough white sac, the sclera. The cornea is the transparent window in this white sac which allows the objects you are looking at to be carried in the form of light waves into the interior of the eye.

The surface of the cornea is where light begins its journey into the eye. The cornea’s mission is to gather and focus visual images. Because it is out front, like the windshield of an automobile, it is subject to considerable abuse from the outside world.

The cornea is masterfully engineered so that only the most expensive manmade lenses can match its precision. The smoothness and shape of the cornea, as well as its transparency, is vitally important to the proper functioning of the eye. If either the surface smoothness or the clarity of the cornea suffers, vision will be disrupted.

CORNEAL LAYERS

• Epithelium  is the thin outermost layer of fast-growing and easily-regenerated cells.
• Bowman’s layer  consists of irregularly-arranged collagen fibers and protects the corneal stroma. It is 8 to 14 microns thick.
• Stroma , the transparent middle and thickest layer of the cornea is made up of regularly-arranged collagen fibers and keratocytes (specialized cells that secrete the collagen and proteoglycans needed to maintain the clarity and curvature of the cornea)
• Descemet’s membrane  is a thin layer that serves as the modified basement membrane of the corneal endothelium.
• Endothelium  is a single layer of cells responsible for maintaining proper fluid balance between the aqueous and corneal stromal compartments keeping the cornea transparent.

Conditions & Research Areas

Bullous keratopathy, fuchs' dystrophy, keratoconus, refractive error, cornea transplants, endothelial keratoplasty (dsek & dmek), anterior lamellar keratoplasty (alk), penetrating keratoplasty (pk), artificial cornea, traveling to indianapolis for your transplant, descemet's stripping only (dso), other treatment options, artificial iris, cataract surgery with advanced lens options, corneal crosslinking, dry eye treatments, glaucoma surgery, lasik/refractive surgery, lens exchange, how the eye works, what is the cornea, how to care for your eyes, financial assistance/help, covid-19 and your transplant, read our latest annual report.

This detailed report includes a letter from our Chairman, Fiscal Year Financial Information, lists of studies, presentations and journal articles and recognition of our generous supporters.

The Journey of Vision

• In order for vision to occur, a series of processes must take place involving all of these structures within the eye and others within the brain. Let’s go on a journey and follow light rays as they travel through the eye to ultimately reach the retina.  All of these structures are needed to bend, or refract, the light so that it focuses properly.  It’s a real “team” effort!
• Light first passes through the cornea at the front of the eye, and then through a watery substance called the aqueous humor which fills small chambers behind the cornea.
• As the light continues, it passes through the pupil, a round opening in the center of the iris.  The iris is the colored part of the eye and it has specialized muscles that function like the f-stop on a camera, changing the size of the pupil from very small to large, and regulating the amount of entering light.
• The lens is the next structure that the light penetrates; it’s attached to muscles which contract or relax in order to change the lens shape.  Changing its shape is what produces the clarity of images that we see at different distances. (The ability to focus decreases as we age and that’s why many adults over 40 years old need reading glasses or bifocals.)
• Next, the light passes through the large back portion of the eye that is filled with a clear, jelly-like substance called the vitreous. From there, the light finally reaches the retina, where rod and cone cells are stimulated to release split-second chemical reactions converting the light to electrical impulses.  Cone cells (typically about 7 million) are in greatest concentration in the central part of the retina called the macula.  This area is responsible for producing sharp, detailed vision and color vision.  An even greater number of rod cells (about 100 million) are found in the retina, away from the macula, and these allow us to see in dimly lit settings.  But with less detail or resolution than the macula.
• When all parts of the visual system are working, the eyes are able to move together, adapt to light and dark environments, perceive colors and accurately evaluate an object’s location in space.  Our eyes are sensitive to contrast differences, and can provide detailed vision, measured as visual acuity.  “Normal” visual acuity is reported as 20/20.  As the second number of this expression gets higher, it tells us that vision is weaker than “normal.”  For instance, “legal blindness” is described as 20/200.  An easy way to understand the meaning of these numbers is that the eye being tested sees at 20 feet what a “normal” eye would see at 200 feet.  People who are “legally blind” may still see well enough to do some of the things they need to do in daily life.

Too Far or Too Close

The role of your brain, corneal research strengthens sight.

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In brief: how does the eye work.

Last Update: December 8, 2021 ; Next update: 2024.

Vision is the result of a complex process. For our brain to be able to create an image of our surroundings, the eye needs to convert light into electrical signals called nerve impulses. These nerve impulses then travel to the brain along the optic nerve. The different parts of the eye each have special, closely coordinated jobs. The main parts of the eye are

• the cornea ,
• the lens, and
• the retina.

The main parts of the human eye

Only the front part of the eye can be seen from the outside. The rest of the eyeball is protected inside the eye socket. It is connected to several muscles that can move the eye to change the direction you are looking in.

• The front part of the eye

The white part of the eye (sclera) is the visible part of the firm outer surface of the eyeball. The colored part of the eye is the iris. It is like a disc with a hole in the middle, which is known as the pupil. The iris has muscles that it can use to make the pupil bigger or smaller. A bit like the aperture of a camera, this controls how much light is let into the eye: When it’s very bright, the iris makes the pupil smaller to prevent “overexposure.” In the dark, the iris makes the pupil bigger to let as much light as possible enter the eye.

The iris and pupil are covered by a transparent layer called the cornea . The main function of the cornea is to protect the eye from foreign objects and injury . Our eyelids, eyelashes and tear fluid do this too. But the cornea also plays a role in vision. It changes the path of the light (refracts the light) on its way into the eye.

The cornea isn't located right on the iris. Instead, it is stretched over it like a dome. The space inside this dome contains a fluid called aqueous humor. This fluid cleanses the eye and supplies the cornea and lens with nutrients.

• The inside of the eye

When rays of light pass through the pupil, they reach the lens right behind it. The lens is attached to muscles through strong fibers. When these muscles contract, the shape of the lens changes. The path of the light entering the eye is then changed (refracted) to different extents depending on the shape. This process, known as “accommodation,” allows the eye to focus on nearby or more distant objects.

Adjusting to nearby and distant objects

The vitreous body is located behind the lens. This gel-like mass gives the eyeball its full, elastic shape. The vitreous body is transparent, like the cornea and the lens. This is an important requirement for good vision. But vision may become cloudy in old age: For example, if the lens is no longer “crystal clear,” it’s known as a cataract . The cornea can also become cloudy in older people. This may be caused by scarring.

Many people have cloudy substances in their vitreous body that are harmless and don’t affect how your vision functions. Sometimes it can seem like small threads or insects are floating around in your field of vision, though. These are called eye floaters. Sometimes the vitreous body becomes so cloudy that it affects your vision and needs to be treated. But this is less common and is usually associated with an eye infection. The vitreous body can also become cloudy if blood enters the eyeball. The back wall of the eyeball is lined with a membrane called the retina. The back part of the eye – which is called the ocular fundus – contains millions of sensory cells. The refraction caused by the lens makes a sharp image of whatever you are looking at appear right there. The sensory cells receive these light signals and convert them to nerve signals .

The retina has two kinds of sensory cells, called cones and rods.

• The cones allow us to see in color.
• The rods are responsible for “black and white” vision. They need less light and make it possible for us to see at dusk and at night.

These different kinds of sensory cells aren’t evenly spread out across the retina. Most of the cones are located roughly in the middle of the ocular fundus, which is called the macula. This is the area in which our vision is the sharpest.

The nerve signals sent by the cones and rods are carried to the brain by the optic nerve. In the brain they are processed and used to create a consciously perceived image, together with information from the other eye.

• Brandes R, Lang F, Schmidt R. Physiologie des Menschen: mit Pathophysiologie. Berlin: Springer; 2019.
• Menche N (Ed). Biologie Anatomie Physiologie. München: Urban und Fischer; 2016.
• Pschyrembel Online . 2021.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. informedhealth.org can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

• Cite this Page InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. In brief: How does the eye work? [Updated 2021 Dec 8].
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How Do We See?

Learn how light travels through the eye and how the visual system allows you to see and experience the world around you.

How do we see?

Let’s follow the light.

• Light enters the cornea, the clear “window” of the eye.
• The cornea bends the light so it passes through the pupil.
• The iris makes the pupil bigger or smaller, which determines how much light gets to the lens.
• The lens angles the light through the clear vitreous to focus it on the retina.
• The retina converts the light into electrical impulses. These impulses travel along the optic nerve to your brain, producing an image.

While it may sound complicated, this happens in less than a second and allows you to see the world around you.

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How does light enter the eye.

Light enters via the clear cornea of the eye. Its intensity is controlled by the adjustable diaphragm, the iris. The light passes through the iris opening called the pupil, and is focused by the lens on the retina. From the retina the light is converted into electrical impulses, conducted by the optic nerve and tract to the occipital cortex or the back part of the brain. For the brain to get the fullest information the image formed should be sharply focused and clear.

What are refractive or focusing errors of the eye? What is accommodation?

The light which enters the eye as parallel rays has to be bent to focus at a point. Refraction means the bending of light rays when they travel from one medium, say air, into another medium, say water, of different density.

The cornea or the clear membrane is the point where the first refraction occurs, for it is denser than air. There are other liquid media in the eye which also bend the light rays, but the most important is the lens. The lens acts as a variable continuous focusing system. It has the ability to become rounder, thus increasing the power or the focusing capacity. It can also become flatter and decrease the focusing capacity. The ability of the lens to change its focus is termed accommodation and is completely under the control of the brain. A blurry retinal image triggers off accommodational effort which clears the image and focuses it to exquisite sharpness.

Another important fact is that the two eyes accommodate or focus together. They cannot work independently.

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Normal Vision

What is normal vision.

To understand how certain problems can affect your child's vision, it’s important to know how normal vision happens. For children with normal vision, the following things happen in this order:

Light enters the eye through the cornea. This is the clear, dome-shaped surface that covers the front of the eye.

From the cornea, the light passes through the pupil. The iris, or the colored part of your eye, controls the amount of light passing through.

From there, it then hits the lens. This is the clear structure inside the eye that focuses light rays onto the retina.

Next, light passes through the vitreous humor. This is the clear, jelly-like substance that fills the center of the eye. It helps to keep the eye round in shape.

Finally, the light reaches the retina. This is the light-sensitive nerve layer that lines the back of the eye. Here the image is inverted.

The optic nerve is then responsible for carrying the signals to the visual cortex of the brain. The visual cortex turns the signals into images (for example, our vision).

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The Nature of Light

Introduction.

Light is a transverse, electromagnetic wave that can be seen by the typical human. The wave nature of light was first illustrated through experiments on diffraction and interference . Like all electromagnetic waves, light can travel through a vacuum. The transverse nature of light can be demonstrated through polarization .

• In 1678, Christiaan Huygens (1629–1695) published Traité de la Lumiere , where he argued in favor of the wave nature of light. Huygens stated that an expanding sphere of light behaves as if each point on the wave front were a new source of radiation of the same frequency and phase.
• Thomas Young (1773–1829) and Augustin-Jean Fresnel (1788–1827) disproved Newton's corpuscular theory.

Light is produced by one of two methods…

• Incandescence is the emission of light from "hot" matter (T ≳ 800 K).
• Luminescence is the emission of light when excited electrons fall to lower energy levels (in matter that may or may not be "hot").

Just notes so far. The speed of light in a vacuum is represented by the letter c from the Latin celeritas — swiftness. Measurements of the speed of light.

Veramente non l'ho sperimentata, salvo che in lontananza piccola, cioè manco d'un miglio, dal che non ho potuto assicurarmi se veramente la comparsa del lume opposto sia instantanea; ma ben, se non instantanea, velocissima…. In fact I have tried the experiment only at a short distance, less than a mile, from which I have not been able to ascertain with certainty whether the appearance of the opposite light was instantaneous or not; but if not instantaneous it is extraordinarily rapid …. Galileo Galilei, 1638 Galileo Galilei, 1638

Ole Rømer (1644–1710) Denmark. "Démonstration touchant le mouvement de la lumière trouvé par M. Roemer de l'Académie des Sciences." Journal des Scavans . 7 December 1676. Rømer's idea was to use the transits of Jupiter's moon Io to determine the time. Not local time, which was already possible, but a "universal" time that would be the same for all observers on the Earth, Knowing the standard time would allow one to determine one's longitude on the Earth — a handy thing to know when navigating the featureless oceans.

Unfortunately, Io did not turn out to be a good clock. Rømer observed that times between eclipses got shorter as Earth approached Jupiter, and longer as Earth moved farther away. He hypothesized that this variation was due to the time it took for light to travel the lesser or greater distance, and estimated that the time for light to travel the diameter of the Earth's orbit, a distance of two astronomical units, was 22 minutes.

• The speed of light in a vacuum is a universal constant in all reference frames.
• The speed of light in a vacuum is fixed at 299,792,458 m/s by the current definition of the meter.
• The speed of light in a medium is always slower the speed of light in a vacuum.
• The speed of light depends upon the medium through which it travels.The speed of anything with mass is always less than the speed of light in a vacuum.

other characteristics

The amplitude of a light wave is related to its intensity.

• Intensity is the absolute measure of a light wave's power density.
• Brightness is the relative intensity as perceived by the average human eye.

The frequency of a light wave is related to its color.

• Color is such a complex topic that it has its own section in this book.
• Laser light is effectively monochromatic.
• There are six simple, named colors in English (and many other languages) each associated with a band of monochromatic light. In order of increasing frequency they are red, orange, yellow, green, blue, and violet .
• Light is sometimes also known as visible light to contrast it from "ultraviolet light" and "infrared light"
• Other forms of electromagnetic radiation that are not visible to humans are sometimes also known informally as "light"
• Nearly every light source is polychromatic.
• White light is polychromatic.

A graph of relative intensity vs. frequency is called a spectrum (plural: spectra ). Although frequently associated with light, the term can be applied to any wave phenomena.

• Blackbody radiators emit a continuous spectrum.
• The excited electrons in a gas emit a discrete spectrum.

The wavelength of a light wave is inversely proportional to its frequency.

• Light is often described by it's wavelength in a vacuum .
• Light ranges in wavelength from 400 nm on the violet end to 700 nm on the red end of the visible spectrum.

Phase differences between light waves can produce visible interference effects. (There are several sections in this book on interference phenomena and light.)

Leftovers about animals.

• Falcon can see a 10 cm. object from a distance of 1.5 km.
• Fly's Eye has a flicker fusion rate of 300/s. Humans have a flicker fusion rate of only 60/s in bright light and 24/s in dim light. The flicker fusion rate is the frequency with which the "flicker" of an image cannot be distinguished as an individual event. Like the frame of a movie… if you slowed it down, you would see individual frames. Speed it up and you see a constantly moving image. Octopus' eye has a flicker fusion frequency of 70/s in bright light.
• Penguin has a flat cornea that allows for clear vision underwater. Penguins can also see into the ultraviolet range of the electromagnetic spectrum.
• Sparrow Retina has 400,000 photoreceptors per square. mm.
• Reindeer can see ultraviolet wavelengths, which may help them view contrasts in their mostly white environment.

How Light Travels: The Reason Why Telescopes Can See the Invisible Parts of Our Universe

Due to how light travels, we can only see the most eye-popping details of space—like nebulas, supernovas, and black holes—with specialized telescopes.

• Our eyes can see only a tiny fraction of these wavelengths , but our instruments enable us to learn far more.
• Here, we outline how various telescopes detect different wavelengths of light from space.

Light travels only one way: in a straight line. But the path it takes from Point A to Point B is always a waveform, with higher-energy light traveling in shorter wavelengths. Photons , which are tiny parcels of energy, have been traveling across the universe since they first exploded from the Big Bang . They always travel through the vacuum of space at 186,400 miles per second—the speed of light—which is faster than anything else.

Too bad we can glimpse only about 0.0035 percent of the light in the universe with our naked eyes. Humans can perceive just a tiny sliver of the electromagnetic spectrum: wavelengths from about 380–750 nanometers. This is what we call the visible part of the electromagnetic spectrum. The universe may be lovely to look at in this band, but our vision skips right over vast ranges of wavelengths that are either shorter or longer than this limited range. On either side of the visible band lies evidence of interstellar gas clouds, the hottest stars in the universe, gas clouds between galaxies , the gas that rushes into black holes, and much more.

Fortunately, telescopes allow us to see what would otherwise remain hidden. To perceive gas clouds between stars and galaxies, we use detectors that can capture infrared wavelengths. Super-hot stars require instruments that see short, ultraviolet wavelengths. To see the gas clouds between galaxies, we need X-ray detectors.

We’ve been using telescopes designed to reveal the invisible parts of the cosmos for more than 60 years. Because Earth’s atmosphere absorbs most wavelengths of light, many of our telescopes must observe the cosmos from orbit or outer space.

Here’s a snapshot of how we use specialized detectors to explore how light travels across the universe.

Infrared Waves

We can’t see infrared waves, but we can feel them as heat . A sensitive detector like the James Webb Space Telescope can discern this thermal energy from far across the universe. But we use infrared in more down-to-Earth ways as well. For example, remote-control devices work by sending infrared signals at about 940 nanometers to your television or stereo. These heat waves also emanate from incubators to help hatch a chick or keep a pet reptile warm. As a warm being, you radiate infrared waves too; a person using night vision goggles can see you, because the goggles turn infrared energy into false-color optical energy that your eyes can perceive. Infrared telescopes let us see outer space in a similar way.

Astronomers began the first sky surveys with infrared telescopes in the 1960s and 1970s. Webb , launched in 2021, takes advantage of the infrared spectrum to probe the deepest regions of the universe. Orbiting the sun at a truly cold expanse—about one million miles from Earth—Webb has three infrared detectors with the ability to peer farther back in time than any other telescope has so far.

Its primary imaging device, the Near Infrared Camera (NIRCam), observes the universe through detectors tuned to incoming wavelengths ranging from 0.6 to 5 microns, ideal for seeing light from the universe’s earliest stars and galaxies. Webb’s Mid-Infrared Instrument (MIRI) covers the wavelength range from 5 to 28 microns, its sensitive detectors collecting the redshifted light of distant galaxies. Conveniently for us, infrared passes more cleanly through deep space gas and dust clouds, revealing the objects behind them; for this and many other reasons, the infrared spectrum has gained a crucial foothold in our cosmic investigations. Earth-orbiting satellites like NASA’s Wide Field Infrared Survey Telescope ( WFIRST ) observe deep space via longer infrared wavelengths, too.

Yet, when stars first form, they mostly issue ultraviolet light . So why don’t we use ultraviolet detectors to find distant galaxies? It’s because the universe has been stretching since its beginning, and the light that travels through it has been stretching, too; every planet, star, and galaxy continually moves away from everything else. By the time light from GLASS-z13—formed 300 million years after the Big Bang—reaches our telescopes, it has been traveling for more than 13 billion years , a vast distance all the way from a younger universe. The light may have started as ultraviolet waves, but over vast scales of time and space, it ended up as infrared. So, this fledgling galaxy appears as a red dot to NIRCam. We are gazing back in time at a galaxy that is rushing away from us.

Radio Waves

If we could see the night sky only through radio waves, we would notice swaths of supernovae , pulsars, quasars, and gassy star-forming regions instead of the usual pinprick fairy lights of stars and planets.

Tools like the Arecibo Observatory in Puerto Rico can do the job our eyes can’t: detect some of the longest electromagnetic waves in the universe. Radio waves are typically the length of a football field, but they can be even longer than our planet’s diameter. Though the 1,000-foot-wide dish at Arecibo collapsed in 2020 due to structural problems, other large telescopes carry on the work of looking at radio waves from space. Large radio telescopes are special because they actually employ many smaller dishes, integrating their data to produce a really sharp image.

Unlike optical astronomy, ground-based radio telescopes don’t need to contend with clouds and rain. They can make out the composition, structure, and motion of planets and stars no matter the weather. However, the dishes of radio telescopes need to be much larger than optical ones to generate a comparable image, since radio waves are so long. The Parkes Observatory’s dish is 64 meters wide, but its imaging is comparable to a small backyard optical telescope, according to NASA .

Eight different radio telescopes all over the world coordinated their observations for the Event Horizon Telescope in 2019 to put together the eye-opening image of a black hole in the heart of the M87 galaxy (above).

Ultraviolet Waves

You may be most familiar with ultraviolet, or UV rays, in warnings to use sunscreen . The sun is our greatest local emitter of these higher-frequency, shorter wavelengths just beyond the human visible spectrum, ranging from 100 to 400 nanometers. The Hubble Space Telescope has been our main instrument for observing UV light from space, including young stars forming in Spiral Galaxy NGC 3627, the auroras of Jupiter, and a giant cloud of hydrogen evaporating from an exoplanet that is reacting to its star’s extreme radiation.

Our sun and other stars emit a full range of UV light, telling astronomers how relatively hot or cool they are according to the subdivisions of ultraviolet radiation: near ultraviolet, middle ultraviolet, far ultraviolet, and extreme ultraviolet. Applying a false-color visible light composite lets us see with our own eyes the differences in a star’s gas temperatures.

Hubble’s Wide Field Camera 3 (WFC3) breaks down ultraviolet light into specific present colors with filters. “Science visuals developers assign primary colors and reconstruct the data into a picture our eyes can clearly identify,” according to the Hubble website . Using image-processing software, astronomers and even amateur enthusiasts can turn the UV data into images that are not only beautiful, but also informative.

X-Ray Light

Since 1999, the orbiting Chandra X-Ray Observatory is the most sensitive radio telescope ever built. During one observation that lasted a few hours, its X-ray vision saw only four photons from a galaxy 240 million light-years away, but it was enough to ascertain a novel type of exploding star . The observatory, located 86,500 miles above Earth, can produce detailed, full-color images of hot X-ray-emitting objects, like supernovas, clusters of galaxies and gases, and jets of energy surrounding black holes that are millions of degrees Celsius. It can also measure the intensity of an individual X-ray wavelength, which ranges from just 0.01 to 10 nanometers. Its four sensitive mirrors pick up energetic photons and then electronic detectors at the end of a 30-foot optical apparatus focus the beams of X-rays.

Closer to home, the Aurora Borealis at the poles emits X-rays too. And down on Earth, this high-frequency, low-wavelength light passes easily through the soft tissue of our bodies, but not our bones, yielding stellar X-ray images of our skeletons and teeth.

Visible Light

Visible color gives astronomers essential clues to a whole world of information about a star, including temperature, distance, mass, and chemical composition. The Hubble Telescope, perched 340 miles above our planet, has been a major source of visible light images of the cosmos since 1990.

Hotter objects, like young stars, radiate energy at shorter wavelengths of light; that’s why younger stars at temperatures up to 12,000 degrees Celsius, like the star Rigel, look blue to us. Astronomers can also tell the mass of a star from its color. Because mass corresponds to temperature, observers know that hot blue stars are at least three times the mass of the sun. For instance, the extremely hot, luminous blue variable star Eta Carina’s bulk is 150 times the mass of our sun, and it radiates 1,000,000 times our sun’s energy.

Our comparatively older, dimmer sun is about 5,500 degrees Celsius, so it appears yellow. At the other end of the scale, the old star Betelgeuse has been blowing off its outer layer for the past few years, and it looks red because it’s only about 3,000 degrees Celsius.

A View of Earth

Scientists use different wavelengths of light to study phenomena closer to home, too.

Detectors in orbit can distinguish between geophysical and environmental features on Earth’s changing surface, such as volcanic action. For example, infrared light used alongside visible light detection reveals areas covered in snow, volcanic ash, and vegetation. The Moderate Resolution Imaging Spectroradiometer ( MODIS ) infrared instrument onboard the Aqua and Terra satellites monitors forest fire smoke and locates the source of a fire so humans don’t have to fly through smoke to evaluate the situation.

Next year, a satellite will be launched to gauge forest biomass using a special radar wavelength of about 70 centimeters that can penetrate the leafy canopy.

💡 Why is the sky blue? During the day, oxygen and nitrogen in Earth’s atmosphere scatters electromagnetic energy at the wavelengths of blue light (450–485 nanometers). At sunset, the sun’s light makes a longer journey through the atmosphere before greeting your eyes. Along the way, more of the sun’s light is scattered out of the blue spectrum and deeper into yellow and red.

Before joining Popular Mechanics , Manasee Wagh worked as a newspaper reporter, a science journalist, a tech writer, and a computer engineer. She’s always looking for ways to combine the three greatest joys in her life: science, travel, and food.

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Refractive errors and refraction: How the eye sees

By Gary Heiting, OD

Schedule an exam

What is a refractive error?

Blurry vision — usually caused by refractive errors — is the main reason a person seeks the services of an eye doctor.

But what does it really mean when we’re told that our vision is blurry because we have a refractive error?

We see the world around us because of the way our eyes bend (refract) light. Refractive errors are optical imperfections that prevent the eye from properly focusing light, causing blurred vision.

The primary refractive errors are nearsightedness , farsightedness and astigmatism .

Refractive errors usually can be “corrected” with eyeglasses or contact lenses , or they can be permanently treated with LASIK and other vision correction surgery (also called refractive surgery).

SEE RELATED: What is ametropia?

How light travels through the eye

In order to see, we must have light. While we don’t fully understand all the different properties of light, we do have an idea of how light travels.

A light ray can be deflected, reflected, bent or absorbed, depending on the different substances it encounters.

When light travels through water or a lens, for example, its path is bent or refracted. Certain eye structures have refractive properties similar to water or lenses and can bend light rays into a precise point of focus essential for sharp vision .

Most refraction in the eye occurs when light rays travel through the curved, clear front surface of the eye ( cornea ). The eye’s natural lens also bends light rays. Even the tear film on the surface of the eye and the fluids inside the eye ( aqueous humor and vitreous ) have some degree of refractive ability.

How the eye sees

The process of vision begins when light rays that reflect off objects and travel through the eye’s optical system are refracted and focused into a point of sharp focus.

For good vision, this focus point must be on the retina . The retina is the tissue that lines the inside of the back of the eye, where light-sensitive cells ( photoreceptors ) capture images in much the same way that film in a camera does when exposed to light.

These images then are transmitted through the eye’s optic nerve to the brain for interpretation.

Just as a camera’s aperture (called the diaphragm) is used to adjust the amount of light needed to expose film in just the right way, the eye’s pupil widens or constricts to control the amount of light that reaches the retina.

In dark conditions, the pupil widens. In bright conditions, the pupil constricts.

Causes of refractive errors

The eye’s ability to refract or focus light sharply on the retina primarily is based on three eye anatomy features: 1) the overall length of the eye, 2) the curvature of the cornea and 3) the curvature of the lens inside the eye.

Eye length – If the eye is too long, light is focused before it reaches the retina, causing nearsightedness. If the eye is too short, light is not focused by the time it reaches the retina. This causes farsightedness or hyperopia.

Curvature of the cornea – If the cornea is not perfectly spherical, then the image is refracted or focused irregularly to create a condition called astigmatism. A person can be nearsighted or farsighted with or without astigmatism.

Curvature of the lens – If the lens is too steeply curved in relation to the length of the eye and the curvature of the cornea, this causes nearsightedness. If the lens is too flat, the result is farsightedness.

More obscure vision errors, known as higher-order aberrations , also are related to flaws in the way light rays are refracted as they travel through the eye’s optical system.

These types of vision errors, which can create problems such as poor contrast sensitivity , are detected through new technology known as wavefront analysis .

Detection and treatment of refractive errors

Your eye doctor determines the type and degree of refractive error you have by performing a test called a refraction.

This can be done with a computerized instrument (automated refraction) or with a mechanical instrument called a phoropter that allows your eye doctor to show you one lens at a time (manual refraction).

Often, an automated refraction will be performed by a member of the doctor’s staff, and then the eye doctor will refine and verify the results with a manual refraction.

Your refraction may reveal that you have more than one type of refractive error. For example, your blurred vision may be due to both nearsighted and astigmatism.

Your eye doctor will use the results of your refraction to determine your eyeglasses prescription .

A refraction, however, does not provide sufficient information to write a contact lens prescription , which requires a contact lens fitting .

Eyeglass lenses and contact lenses are fabricated with precise curves to refract light to the degree necessary to compensate for refractive errors and bring light to a sharp focus on the retina.

Vision correction surgeries such as LASIK aim to correct refractive errors by changing the shape of the cornea, so that light rays are bent into a more accurate point of focus on the retina.

See an eye doctor

The only way to know for sure if you are seeing as clearly as possible is to see an eye doctor .

READ NEXT: How far can the human eye see?

Page published on Monday, October 21, 2019

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• Chef Ton’s Bangkok: Street Bites, Swanky Bars, Late-Night Grubs to Red-Light District

In our 'My City With' series, the MICHELIN Guide invites you to discover Bangkok through the eyes and palate of Chef Thitid “Ton” Tassanakajohn, a renowned chef and true son of the Thai capital.

Thailand Editor's Pick Travel My Bangkok Bangkok

Homeboy Thitid “Ton” Tassanakajohn —aka Chef Ton —takes you on a whirlwind tour of his favourite Bangkok. Dive into a day filled with nostalgic home-cooked meals, a quirky shopping spot, multiple vibrant late-night soirées (including a red-light district, yes, you read that right), and a stop at the chef’s top pick for a glass of vino. Cap it all off with a fun stay in the city that (seriously) never sleeps. Tassanakajohn’s culinary passion, nurtured from childhood, led him to abandon a brief banking career to pursue his true calling. Educated at the Culinary Institute of America with a focus on wine, he apprenticed at top New York restaurants before returning to Thailand to establish Le Du as one of the pioneers in the Thai fine dining scene. At Le Du, meaning "season" in Thai, his modern Thai cuisine using local, seasonal ingredients earned him a MICHELIN Star.

To claim he’s one of the busiest chefs in the country is no understatement. Juggling never-ending international collaborations and managing multiple restaurants—including four 2024 MICHELIN-listed gems—he oversees Baan , a homestyle Thai eatery; Samut in Phuket, showcasing southern Thai flavours; Lahnyai , a modern interpretation of royal Thai cuisine sourced from the cremation cookbooks of princesses from 1987 to 1992, and a grand venture, Nusara , a tribute to his late grandmother. Alongside his younger brother, he manages Nusara, which offers one of the most charming old-town views in Bangkok’s historic district. Tassanakajohn has also been a notable figure championing Thai cuisine among his culinary peers across Asia. He’s been tirelessly introducing them to his favourite eateries and trendy spots in Bangkok. But you needn’t be a chef to catch a glimpse of where this local culinary celebrity dines and hangs out. Here are the hotspots he frequents in Bangkok. READ:  5 MICHELIN Hotels to Stay Along the Bangkok Riverside

For a date night: Potong “I like Potong because it is the heart of what we might call the hippest and currently the most happening area of Bangkok, Songwat. A hundred-year-old house of Chef Pam, for the 5th generation. This may already sound quite romantic in a Bangkok way. Plus, it shows the original and beautiful art of old Bangkok. The journey from the first floor to the fifth will awaken all your senses with amazing experiences and creative food from the chef. It will be a night to remember for both of you.” At the 2024 one MICHELIN Star Potong, Chef Pichaya “Pam” Soontornyanakij blends traditional Thai-Chinese flavours with modern flair in a historic Sino-Portuguese building. Enjoy a vibrant atmosphere from the ground-floor bar to the rooftop lounge, and don’t miss the standout aged duck breast. A stroll through the old Thai-Chinese market adds a unique and memorable touch to the visit. 422 Vanich 1 Road, Samphanthawong, Bangkok.

For a true Bangkok experience: Wat Po and the Grand Palace

For a true street food experience: Chan Road and Guay Jub Mr. Jo

For the best place to shop: JJ Market aka Chatuchak Market

For a cuppa joe: School Coffee x Warm Batch Roasters

For a glass of wine or more: Wine Merchant

For a home cook meal: Baan Pee Lek

For the best view of Bangkok: EA Rooftop at The Empire

For a perfect stay(cation): Kimpton Maa-Lai Bangkok

For a place to let your hair down: Rim Bangkok

For a night you won’t forget: Phat Phong

For a late-night snack: banthat thong road.

READ FURTHER: Chalee Kader's Bangkok: Street and Fancy Eats, Wine Bars, Sneaker Shops, and More Illustration image © Thitid Tassanakajohn/ Instagram

After over a decade of writing for leading luxury and lifestyle publications, and dining and wining with world’s famous, this Bangkokian finds herself as a Digital Editor of the MICHELIN Guide Thailand and Vietnam. She enjoys exchanging cultural views over a glass of wine or Gin Rickey. If not on the beach, she can be found at the gym, catching a plane, or at home reading Agatha Christie’s novels.

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