Blindness

What is blindness?

Blindness is the partial or full loss of sight in your eyes. Some people who are blind can’t see anything at all. Most people who are legally blind can see some things, but they struggle with their vision.

You are legally blind if:

• you can only just read a sign that’s 6 metres away, but that someone with normal vision can read from 60 metres away; or
• your field of vision is less than 20 degrees in diameter (sometimes called ‘tunnel vision’).

You have low vision if you can’t see properly, your eyesight can’t be improved as much as you’d like by using glasses or contact lenses, and your life is affected by your poor vision.

If you have colour ‘blindness’, you are not blind. People with colour blindness have problems recognising some colours, or see them differently from other people. 

What are the symptoms of blindness?

Different people have different experiences of vision loss or blindness, depending partly on what is causing it.

If you have macular degeneration, for example, you might start to lose the sight out of the side of your eyes. 

If you have cataracts, symptoms include blurred vision, double vision and problems with glare.

Some people have problems seeing properly at night, or have tunnel vision (where they can see things straight in front of them, but can’t see things off to the side). Others start to see things that aren’t there, or see flecks or spots that won’t go away.

What causes blindness?

The most common causes of vision loss and blindness in Australia are macular degeneration, cataracts, diabetic retinopathy and glaucoma. These all become more common as someone gets older.

Other causes of blindness include:

• genetic conditions, such as Usher syndrome or retinitis pigmentosa, which cause problems from birth or from childhood
• accidents and injuries that damage the eyes

Macular degeneration

If you have macular degeneration, the cells in and under your retina, which is at the back of your eye, will have been damaged. There are 2 types of macular degeneration – dry and wet. People with the dry form slowly lose vision in the centre of the eye. People with the wet form can lose their vision suddenly. 

Cataract

A cataract is a cloudiness of the lens, which sits towards the front of the eye and helps focus the light image so someone can see clearly. Cataracts can just happen, especially as someone gets older. They’re also more common in people who spend a lot of time in the sun without sunglasses, who have diabetes or high blood pressure, who smoke or who have been on certain medications such as statins or hormone replacement therapy — for a long time.

Diabetic retinopathy

Diabetic retinopathy gradually causes blurred or distorted vision, problems seeing at night, sensitivity to glare, problems with balance and double vision. 

Glaucoma

Glaucoma is the name for a group of eye diseases that cause damage to the optic nerve. The most common cause of optic nerve damage is pressure inside the eye. 

Glaucoma starts by affecting the outer edge of the vision. It usually happens gradually, and people may not know they have it.

How is blindness diagnosed?

See a doctor or optometrist if you are worried that you have vision problems. They will examine your eyes and do vision tests. You might be referred to an ophthalmologist, a doctor who specialises in eye conditions.

Regular eye tests are important. Early detection of many eye conditions can save your sight.

How is blindness treated?

Treatments for vision loss and blindness depend on what problem you have with your eyes. Sometimes no treatment is available.

If you have macular degeneration, an ophthalmologist will try to stabilise and maintain your vision for as long as possible. One option involves regularly injecting medicines into your eye. 

If you have a cataract, your ophthalmologist might remove the cloudy lens in your eye and replace it with a plastic lens.

If you have diabetic retinopathy, there are different forms of surgery and laser surgery that can help.

If you have glaucoma, eye drops can help. Laser surgery or an operation may be an option for some people.

Living with blindness

You might have to change your daily activities and make changes to your house. Some things might help, like magnifiers, better lighting, and screen reading technology.

Vision Australia offers lots of advice and support.

Eye checks

Regular eye tests are very important. Talk to your doctor or optometrist about the tests you should have, and how often you should have them. Vision Australia has more information on eye tests.