We normally hear people say that they are colour blind when they erroneously classify one color as another colour. But most of us are not really aware of what color blindness is. One common question is whether or not it is an eye disease. Here’s a look at some information about color blindness to help us determine if it should be classified as an eye disease.
Colour blindness is a vision problem that denotes trouble seeing the colours blue, green, red or a combination of these colours. It does not involve a total failure of seeing all colours. In most cases the term colour blindness therefore is a misnomer – Colour deficiency is possibly better terminology.
• Difficulty in differentiating between colours
• You can see some colors but not other colours.
• You only see a few shades of a particular colour.
• You only see gray, white and black – this condition is very rare and called acromatopsia.
• Most cases of colour blindness are hereditary or genetic which means it is present at birth. Normally, people have three types of cone cells in the eye with each type sensing green, blue or red light. Most cone cells are located in the macula or the central part of the retina. When you are born colour blind, it’s possible that you do not have one of these types of cone cells or they do not function right away. You may see one of the three basic colours but you see a different shade.
• Eye diseases like macular degeneration, diabetic retinopathy, glaucoma or cataracts
• Side effects of some medications
• Injury to the eye.
Here are some tests that may be performed to determine if you are suffering from colour blindness or from other eye diseases:
• You may be asked to group together chips of similar colours.
• You may be asked to look at colored dots and to find a pattern like a letter or number in them. The patterns will help your optometrist determine the colours you are having trouble with. Most people are familiar with this test and is called the Ishihara test. Lay people over the years refer to it as the “confetti test”, as the coloured dots look like confetti.
• For children, eye exams may be performed between the ages of 3 and 5. Experts recommend that children undergo vision screening at least once before they enter school or between the ages of 3 and 4.
• Colour deficiency is far more common in males. In most cases it is a genetic defect that is passed on from the mother (who is normally a carrier but does not exhibit the defect) to the son. This type of genetic inheritance is called X-Linked.
• Approximately 7% of males are colour deficient, whereas only about 0.4% of females are colour deficient. To explain this in detail is well beyond the scope of this post.
• Inherited colour blindness cannot be corrected or treated.
• Wear coloured contact lenses to help differentiate between colours. However, these do not provide normal colour vision and they can even distort objects.
• If your colour blindness is caused by an eye disease, the underlying condition should be treated. For instance, if a cataract is causing your colour blindness, your cataract should be removed surgically to improve your colour vision.
• Learn to depend on other cues like location or brightness instead of relying on colours. For instance, you can memorize the order of the lights in a traffic signal.
• Wear anti-glare glasses. Studies show that colour blind people can better differentiate between colours when there is less brightness and glare.
Strictly speaking, it may not be accurate to classify color blindness as an eye disease. It may be more accurate to call it a vision problem. While it may not appear serious, you should pay attention to its symptoms as they may be indicative of a more serious eye disease occasionally.