Find a store
 Menu

Eye anatomy: parts of the eye

Discover how your eye works with our comprehensive guide to eye anatomy. Learn about each part of the eyeball and how they work together.

Eye anatomy overview

The human eye is one of the most sophisticated organs in your body, with multiple parts working together to capture light, focus it, and convert it into electrical signals your brain interprets as vision. Your eye is like a tiny camera and every part plays a role in helping you see.

How the eye works

To understand, it helps to follow how light travels through your eye.

  1. 1 of 6

    Cornea

    This is a see‑through, dome‑shaped front layer that covers the iris, pupil, and anterior chamber. It provides about 70% of your eye's focusing power by refracting (bending) light as it enters. Irregularities in the cornea's shape can cause astigmatism, where light doesn't focus properly on the retina.

  2. 2 of 6

    Iris and pupil

    The iris is the coloured part of your eye containing muscles that control the pupil size. The pupil is the dark opening that allows light to enter. In bright conditions, the pupil constricts (gets narrower); in dim light, it dilates (gets wider) to let more light in.

  3. 3 of 6

    Lens

    Located behind the iris, the lens provides 30% of your eye's focusing power and can change shape for near and distance vision. As we age, the lens loses flexibility, leading to presbyopia where near vision becomes difficult.

  4. 4 of 6

    Retina

    The light‑sensitive tissue lining the back of your eye that converts light into electrical signals. The retina contains photoreceptors (rods and cones) that detect light and colour, sending signals via the optic nerve to your brain.

  5. 5 of 6

    Aqueous Humour

    The clear fluid filling the front chambers of your eye. It maintains eye pressure, provides nutrients to tissues without blood vessels, and removes waste. Problems with drainage can lead to glaucoma.

  6. 6 of 6

    Vitreous Humour

    The gel‑like substance filling the large cavity behind the lens. It helps maintain the eye's shape and allows light to pass through to the retina. Changes with age can cause floaters and flashes.

What are the main parts of the eye?

The anatomy of the eye includes several key structures working together for vision. The front of the eye contains the cornea, iris, pupil, and lens, which focus light. The middle contains the aqueous and vitreous humour that maintain eye shape and pressure. The back contains the retina, macula, and optic nerve that process light into vision. Understanding eye anatomy helps explain how conditions like short sightedness (myopia) and astigmatism affect your sight.

Let’s get your vision sorted

Noticed your eyes hurting, or a change in your sight? Whether it’s something new or something that’s been bothering you for a while, we’re here to help.
Book an eye test

Muscles in the eye

The anatomy of the human eye includes six muscles that control eye movement. Each eye has four rectus muscles (superior, inferior, medial, lateral) that move the eye up, down, inward, and outward. Two oblique muscles (superior and inferior) provide rotational movements. These eye anatomy muscles must work in perfect coordination for proper vision, depth perception, and eye alignment. Problems with these muscles can cause double vision or eye strain.

Book an eye test

A diagram of how the eye works

The diagram of an eye shows how light travels through each part to create vision. Light enters through the cornea, passes through the aqueous humour and pupil, gets focused by the lens, travels through the vitreous humour, and reaches the retina where it's converted to electrical signals sent to the brain via the optic nerve.

1. Light enters the cornea

The clear, dome‑shaped cornea provides most of your eye's focusing power, bending light rays as they enter your eye.

2. Iris controls light entry

The coloured iris adjusts the pupil size to regulate how much light enters the deeper parts of your eye, protecting the retina in bright conditions.

3. Lens focuses the image

The flexible lens changes shape to focus light precisely on the retina, allowing you to see objects at different distances clearly.

4. Retina processes light

Light‑sensitive photoreceptors in the retina convert light into electrical signals that travel via the optic nerve to your brain.

Let’s get your vision sorted

Noticed your eyes hurting, or a change in your sight? Whether it’s something new or something that’s been bothering you for a while, we’re here to help.

Book an eye test

What causes eye problems?

Problems with eye anatomy can affect different parts of your vision system. Issues with the cornea or lens can cause focusing problems, while retinal conditions can affect how light is processed. Understanding the anatomy of eye structures helps explain why conditions develop and how they're treated.

Who's more likely to get eye problems?

People with certain risk factors are more likely to experience eye problems. This includes those with diabetes who may develop diabetic retinopathy, older adults who may develop cataracts or glaucoma, and people with family history of eye conditions.

Book an eye test

How are eye problems diagnosed?

An optometrist can diagnose eye problems by examining all parts of your eye anatomy. They use specialised equipment to look at the front and back of your eye, test your vision, and check how well your eye muscles work together. Regular eye tests help detect problems early when treatment is most effective.

An eye care professional smiles while talking to two patients in an examination room with medical equipment and computer monitors.

Patient history

Your optometrist will ask about your symptoms, any previous eye problems, and your general health to understand your eye health.

Vision testing

Comprehensive tests check how well each part of your visual system works, including tests for refractive errors and colour vision.

Eye examination

Using specialised equipment to examine the cornea, lens, retina, and optic nerve for signs of disease or damage.

How are eye problems treated?

Treatment for eye problems depends on which part of the eye anatomy is affected. Refractive errors affecting the cornea or lens can often be corrected with glasses or contact lenses. More serious conditions affecting the retina or optic nerve may require medical treatment or surgery. Early detection through regular eye tests is key to successful treatment.

Book an eye test

When eye problems need medical help

While some vision changes are normal with age, certain symptoms require prompt attention. Understanding your eye anatomy helps you recognise when problems might be serious and need professional care.

Corrective lenses

For refractive errors like myopia, hyperopia, or astigmatism, glasses or contact lenses can correct focusing problems by compensating for irregularities in the eye's anatomy.

Medical treatment

Conditions like glaucoma may require eye drops or other medications to reduce eye pressure and protect the optic nerve from further damage.

Surgery

For conditions like cataracts, surgery to replace the cloudy lens with a clear artificial lens is a common and highly successful treatment.

Preventing eye problems

While not all eye problems can be prevented, you can take steps to protect your eye health and reduce your risk. This includes wearing sunglasses to protect from UV damage, eating a healthy diet rich in vitamins, not smoking, and having regular eye tests to detect problems early.

Frequently Asked Eye Anatomy Questions

Did you know?

AA Members are entitled to a free eye test (valued at $60), once every two years. Remember to present your AA Membership card in‑store.

Book an appointmentSee more eye conditions

Written with care and checked for accuracy

https://images.ctfassets.net/uuaxywrybmpn/5pPERqy14wtRHzP8smUW8/e47ab2cc70b9f2c499df4cd6096c4ed9/Human_Eye_2.jpg

Amy Giang

B. Optom

Amy Giang graduated from the University of Melbourne in 2011 with a Bachelor of Optometry and is therapeutically endorsed. She brings over a decade of experience across private practice and corporate optometry in both regional and metropolitan settings.

After practising at Specsavers Melbourne CBD West, Amy transitioned into her current role as Clinical Services Development Consultant for Australia and New Zealand. In this role, she collaborates to deliver clinical technology solutions, empowering optometrists and enhancing the patient experience.

Common eye health conditions

Find out more

  • A man undergoes an eye exam, looking into a slit lamp while an eye care professional examines his eye.

    Why do I need an eye test?

    Eye tests play a huge part in making sure your eyes stay healthy.

    Check your vision
  • A optometrist operates an eye examination machine while an older man sits in front of it.

    Your store visit explained

    At Specsavers we are focused on caring for your eyes and giving you the best possible vision.

    What to expect in‑store
  • A friendly optometrist giving advice to a patient in the test room.

    More on eye tests

    An eye test is not just about getting glasses – it is a vital health check for your eyes.

    All about eye tests

Let's get your vision sorted

Noticed a change in your sight? Whether it’s something new or something that’s been bothering you for a while, we’re here to help.

Book an eye test