Braille and tactile signs are critical for people with various vision impairments, and not just for use by people who are blind. The most common eye conditions that cause blindness and low vision are as follows:
Aged Related Macular Degeneration
Age-related macular degeneration is the leading cause of severe vision impairment in people aged over 40 years in Australia. It is also referred to as AMD or ARMD.
Albinism
Albinism is an inherited condition. It affects the eyes and skin of some individuals, and only the eyes of others. It results from the body's inability to produce normal amounts of a pigment called melanin.
Cataracts
A cataract is a clouding of the clear lens in the eye and is one of the leading causes of vision impairment. While cataracts most commonly occur in those who are older, they can develop in younger people as well. Some people are born with a cataract.
Charles Bonnet Syndrome
This syndrome is characterised by the presence of complex visual hallucinations seen by people who are vision impaired.
The hallucinations can involve detailed images of people, buildings or simple patterns of straight lines. This experience can be pleasant but can sometimes cause distress. People who have Charles Bonnet Syndrome are aware that these images are not real but they may worry that it is an early sign of mental illness.
Cortical Vision Impairment (CVI)
Cortical vision impairment (CVI) can be either a temporary or a permanent vision impairment caused by the disturbance of the visual cortex or posterior visual pathways of the brain. The degree of neurological impairment depends upon the time of onset and the location and intensity of the damage. The eyes may function normally but the visual systems of the brain do not consistently understand or interpret what the eyes see.
Diabetic Retinopathy
Diabetic retinopathy occurs when the tiny blood vessels inside the retina at the back of the eye are damaged as a result of diabetes. This can seriously affect vision and in some cases cause blindness.
Glaucoma
Glaucoma is a common form of eye disease that often runs in families. It affects the optic nerve connecting the eye to the brain. Glaucoma is often caused by high intraocular pressure, a result of a blockage in the eye's drainage system. Early detection and treatment can prevent vision loss in most cases.
Leber's Congenital Amaurosis
Leber's Congenital Amaurosis (LCA) is an inherited condition which is present from birth. The extent of vision loss varies, but it can be quite severe and a baby may be born with very poor vision or may even be totally blind.
Keratoconus
Keratoconus is an eye condition that causes the clear front surface of the eye (the cornea) to thin and bulge forward. The bulging cornea affects the way light hits the retina at the back of the eye, causing distorted vision.
Nystagmus
Nystagmus refers to rapid involuntary movements that may cause one or both eyes to move from side to side, up and down or around in circles.
Optic Atrophy
Optic Atrophy is the result of degeneration or damage to the optic nerve. The optic nerve transports visual information from the eye, to an area of the brain where it is processed.
Retinitis Pigmentosa
Retinitis Pigmentosa (RP) is a genetic eye condition that causes cells in the light-sensitive retina, located at the back of the eye, to degenerate slowly and progressively. The condition can vary greatly. While many people with RP retain limited vision throughout their lives, others will lose their sight completely.
Stargardt's Disease
Stargardt's disease is a type of macular degeneration that typically surfaces before the age of 20. It causes a progressive loss of central vision of both eyes, but does not affect peripheral vision.
Stroke
Stroke happens when the blood flow to the brain is disrupted, cutting off oxygen supply and leading to brain cell death or damage. In some cases, blood vessels spontaneously burst causing a haemorrhage (bleeding). A stroke is sometimes referred to as cerebral vascular accident (CVA).