Chronic illnesses which can lead to colour blindness include Alzheimer’s disease, diabetes mellitus, glaucoma, leukaemia, liver disease, chronic alcoholism, macular degeneration, multiple sclerosis, Parkinson’s disease, sickle cell anaemia and retinitis pigmentosa.
Accidents or strokes that damage the retina or affect particular areas of the brain/eye can lead to colour blindness.
Medications such as antibiotics, barbiturates, anti-tuberculosis drugs, high blood pressure medications and several medications to treat nervous disorders may cause colour blindness.
Industrial or environmental chemicals such as carbon monoxide, carbon disulphide and some containing lead can also cause colour blindness.
Age – in people over 60 years of age physical changes can occur which might affect a person’s capacity to see colours.
Most people who acquire colour vision deficiency retain some ability to perceive all colours and to them the world begins to appear similar to the way it appears to vision of someone with anomolous trichromacy (click here for more information).
Unlike inherited colour blindness , acquired colour blindness can vary over time. Symptoms may be mild and remain stable or they can be severe and progress to more serious forms of colour blindness, such as monochromatism, very quickly. Often the cause of colour blindness determines how severe the symptoms will be.