What are eyes?

Eyes are the organs we use to see. In some ways, they work like a camera.

There are many parts that make up an eye. These parts work together to allow you to see shapes and colours.

What is the function of the eyes?

Your eyes catch light and send messages to your brain. Your brain organises these messages together to let you see your surroundings. You can recognise faces, notice fine details and see colours. This is also known as your sight or vision.

Together with your ears and muscles, your eyes also help you keep your balance.

What are the different parts of the eyes?

Your eye has many parts that help capture light. If you look at one of your eyes in the mirror, you can see:

• the iris, which is the coloured part of your eye
• the cornea, which is the clear dome over your iris
• the pupil, which is the black hole in the centre of your iris
• the sclera, which is the white part of your eye
• the conjunctiva, a thin layer of tissue that lines the inside of your eyelids and sclera

Other parts of your eye that you can't see are:

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

How do eyes work?

Light reflects from an object when you look at it. This light enters your eye through your pupil. Your pupil, cornea, iris and lens focus the image. Then it travels to the centre of your retina.

The retina is a layer that covers the back of your eye. It has millions of nerve cells that together form a long nerve called the optic nerve. The optic nerves from both of your eyes join inside your brain. Here they work together.

When light stimulates the nerve cells, they send messages to your brain. Your brain uses the information from each optic nerve to create vision. This allows you to see.

What medical conditions are related to the eyes?

Here are 5 common eye conditions that affect Australians:

• macular degeneration and other retinal diseases
• cataracts
• glaucoma
• diabetic retinopathy
• refractive errors, also known as vision impairments

Some people are born with vision impairments. This can be caused by certain genetic conditions, such as albinism or colour blindness.

Vision can also be damaged by:

• eye infections
• eye cancer
• an accident or injury
• diabetes
• dermal fillers
• getting older

Vision Impairments

Vision impairments (difficulties) are the most common eye problems. One common example is known as ‘refractive errors’. These cause blurred vision. The most common types of refractive errors are:

• short-sightedness — causes distant objects to look blurry
• far-sightedness — makes close objects look blurry or you might be able to focus but get tired eyes or headaches
• astigmatism — where the cornea or lens in the eye is not perfectly curved
• presbyopia — when the eyes can't focus on close objects as well as you get older

Eye infections

Eye infections include:

• conjunctivitis — where the white part of the eye becomes pink or red
• trachoma — causes red, sticky eyes
• corneal ulcer — causes red, painful eyes and you might feel like your eye has something in it
• stye — a small, painful lump on the outside or inside of your eyelid

Eye infections are caused by or associated with:

• bacteria
• viruses
• allergies and irritants
• poor hygiene

Eye infections can cause red, itchy, painful eyes, and can sometimes cause vision loss if not treated quickly.

How can I take care of my eyes?

It is important to look after your eyes. Eye problems can affect your education, work, social life and mental health.

Most eye problems can be prevented. Here’s how to take care of your eyes:

• have your eyes checked regularly
• protect your eyes from sunlight by wearing a hat and UV protective sunglasses
• protect your eyes from injury at home and work
• wash your hands and avoid touching your eyes to prevent eye infections
• limit screen time on devices such as your computer an phone to prevent eye strain and dryness
• eat a healthy diet rich in green leafy vegetables, fish, linseeds, vitamins and minerals to help prevent macular degeneration
• avoid smoking

Getting your eyes checked

Optometrists are qualified health professionals and can help diagnose vision problems through eye tests. They can also help treat and manage vision problems.

It is recommended to have your eyes checked every 2 years. If you have an eye condition or risk factors you may need to check your eyes more often.

Even if you aren't worried about your vision, it is important to have regular eye checks to:

• check your eye health
• identify any unnoticed problems

You should also see an optometrist if you notice any changes in your vision. Glasses or contact lenses can often help with blurry vision. It is also important to have your children’s eyes checked regularly.

Resources and support

You can find out more about eye conditions through Vision Australia or read more about taking care of your eyes.

You can also call the healthdirect helpline on 1800 022 222 at any time to speak to a registered nurse (known as NURSE-ON-CALL in Victoria) for more information and advice.

Aboriginal and Torres Strait Islanders

Visit the Aboriginal and Torres Strait Islander Health Performance Framework website for information on eye health for Aboriginal and/or Torres Strait Islander people.