Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

Light enters the eyes through the cornea and is converted into electrical signals, that your brain converts into sight.

Light enters the eyes through the cornea and is converted into electrical signals, that your brain converts into sight.
beginning of content


2-minute read

Your eyes allow you to see the shapes and colours of the world around you. They are sometimes described as your windows to the world.

Parts of the eye

Your eye is a globe about 2.5 cm across. It is not perfectly round.

If you look at one eye in the mirror, you can see:

  • the iris, which is the coloured part
  • the cornea, which is the clear dome over the iris
  • the pupil, which is the black hole in the centre of the iris
  • the sclera, which is the white part
  • the conjunctiva, which is a thin layer of tissue covering the front of your eye, except the cornea

Others parts you can’t see are:

  • the lens, which sits behind the pupil
  • the retina, which is the inside of the back of the eye
  • the optic nerve, which is at the back of the eye

How the eye works

The eye converts light into electrical signals that your brain converts into sight.

Light enters your eye through your cornea, then continues through the pupil and lens.

The cornea and lens focus the light onto the retina.

The retina is a layer of nerve tissue that includes:

  • rods, which identify shapes and movement
  • cones, which detect detail and colours

Rods and cones absorb light signals, change them into nerve impulses, and send them to your brain via the optic nerve.

Your brain recognises the nerve impulses as a visual image.

Causes of vision loss

Blindness and poor vision can be caused by:

  • disease and infections
  • accidents
  • exposure to light or chemicals
  • diabetes

Some people have vision impairment when they’re born, or soon after birth.

Some eye conditions can cause damage to your vision.  You should see a doctor or optometrist if you’re worried about changes in your vision.

For many people with blurry vision, glasses or contact lenses will help.

Read more about eye conditions.

Tips for healthy eyes

To keep your eyes healthy:

  • have your eyes checked every 2 years
  • protect your eyes from sunlight — wear a hat and sunglasses with UV protection
  • eat healthily — green leafy vegetables, fish, linseeds, and some vitamins and minerals can help prevent macular degeneration
  • protect your eyes from injury at home and work
  • avoid smoking

If you have children, have their eyes checked regularly, especially if they say they can’t see clearly.

Read more about eye care.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: January 2020

Back To Top

Need more information?

These trusted information partners have more on this topic.

Top results

Driving and Eye Health - Vision Initiative

Driving and Eye Health Even a small loss of vision can affect your driving

Read more on Vision Initiative website

Sun and eye health - Vision Initiative

Sun and eye health When outside, it is important to protect your eyes from UV rays (sunlight)

Read more on Vision Initiative website

About eye health - Vision Initiative

About eye health By 2020, over 800,000 people will be affected by blindness or vision loss unless they become proactive about saving their sight

Read more on Vision Initiative website

Eye health in Australia - Vision Initiative

Eye health in Australia As the population in Australia ages, the number of people who are blind or have vision loss is expected to be over 800,000 by 2020

Read more on Vision Initiative website

Eye health professionals | Vision Australia. Blindness and low vision services

Roles of eye health professionals You may come across four types of eye health professionals:

Read more on Vision Australia website

Good habits for good eye health - Vision Initiative

Good habits for good eye health Many eye conditions have no symptoms until it is too late

Read more on Vision Initiative website

Eye health | Vision Australia. Blindness and low vision services

Taking care of your eyes can be a daunting proposition, and it’s important that you take the time to do it properly. The following links take all the guesswork out of eye health, covering everything from how your eye health is tested, the roles and functions of different types of eye health professionals, and also some basic tips to get you started on your way to protecting your vision.

Read more on Vision Australia website

Eye health | Australian Government Department of Health and Aged Care

Illness, injury and ageing can affect your eyesight, so it’s important to keep your eyes as healthy as possible. Find out what we’re doing to help improve eye health in Australia and prevent vision loss.

Read more on Department of Health and Aged Care website

More than meets the eye: The link between eye health and nutrition | Nutrition Australia

Ever wondered how our nutritional habits have an impact on eye health? Well, there’s more than meets the eye – with a myriad of nutrients…

Read more on Nutrition Australia website

Eye health in remote communities - NT.GOV.AU

The opthalmology outreach team can visit your community to check the health of your eyes.

Read more on NT Health website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Government of South Australia, health department logo Tasmanian government logo Victorian government logo Government of Western Australia, health department logo

Healthdirect Australia acknowledges the Traditional Owners of Country throughout Australia and their continuing connection to land, sea and community. We pay our respects to the Traditional Owners and to Elders both past and present.