What are low vision eye conditions?

What are low vision eye conditions?

Low vision refers to a condition where an individual experiences vision loss that cannot be corrected with glasses, medical intervention, or surgery. People with low vision may have some useful vision left. Low vision affects each person in different ways dependent on the cause for low vision. Low vision is often categorised as early, moderate, or severe, and may not necessarily follow a linear pattern of development. Some diseases can cause a gradual and progressive loss of vision, whereas others may cause a more acute, or sudden, loss of vision and limited gradual progression.

The definition of legal blindness does not necessarily mean a person sees nothing at all. Legal blindness is a term often used by government agencies to determine potential entitlement levels of government support for people who experience more advanced low vision. Your eye care provider can let you know what stage of low vision you are considered to be.

The most important thing to know is that having low vision does not mean you need to stop doing the things that you enjoy, it only means that you need to learn ways to do these things differently.

Common low vision conditions

Age-related macular degeneration (AMD)

Age-related macular degeneration is caused by damage to the cells in the macula which is part of the retina at the back of your eye. Your macula is responsible for your fine vision, allowing you to read, see fine detail, and distinguish colour. AMD causes loss of your central vision with symptoms like blurred vision, dark patches, or distortion of vision. AMD is one of the main causes of low vision in Australia with about one in seven Australians over the age of 50 years having some signs of AMD.

Cataracts

Cataracts are a progressive clouding of the lens inside the eye, and they can form in one or both eyes. The lens in the eye sits behind the iris and helps to bend and focus the light rays entering the eye to create clear images on the back of the eye, like the lens of a camera. The formation of cataracts prevents a clear image from forming on the retina.

Diabetic retinopathy

Diabetic retinopathy is an eye condition which is a complication of diabetes. Diabetic retinopathy can cause haemorrhages at the back of the eye and the growth of abnormal blood vessels. This can result in symptoms like blurred vision or having dark patches in your vision.

Glaucoma

Glaucoma is often referred to as ‘pressure in the eye’. Glaucoma is a group of conditions typically characterised by increased pressure within the eye (intraocular pressure or IOP) that can damage the optic nerve. Damage to the optic nerve may lead to vision loss which starts in your peripheral (side) vision and it often has no early symptoms. One in 50 Australians will develop glaucoma in their lifetime.

Stroke

A stroke happens when the brain doesn’t have enough oxygen due to a sudden interruption of its blood flow. Due to the lack of oxygen, cells in the brain can start to die, potentially causing permanent damage. This can result in vision loss, with symptoms including a loss of peripheral (side) vision, blurry vision, or diplopia (double vision). More than 440,000 Australians are living with the effects of stroke.

Retinal vascular occlusion

Retinal vascular occlusion happens when there is a blockage in one of the blood vessels in the retina, that is obstructing or completely blocking the normal blood flow to or from retina. If the blockage affects the blood flow in the retina, it can result in a lack of oxygen reaching the retinal cells, potentially leading to blood pooling or bleeding and causing damage to the retina.

There are many other eye conditions which may cause low vision, and your eye care professional is your best source of information on your specific condition. Additionally, many conditions often have no symptoms in the initial stages of disease. For this reason, regular eye checks are the best way to preserve sight during all the stages of life.

For more information

Visit:

• Macular Disease Foundation Australia
• Glaucoma Australia
• Diabetes Australia
• Stroke Foundation

Always speak to your GP and eye care professional about the best treatment options for you.