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“I thought you were going to match your shirt and tie?” Do other people sometimes tell you that the colour you think you are seeing is wrong? This is an early sign that you have a colour vision deficiency.
Colour vision deficiency is a condition that is inherited that affects men more frequently than women. Also commonly known as colour blindness it is not in fact a form of blindness at all, but sufferers will have problems difficulty distinguishing certain colors, such as red and green or blue and yellow.
The most common form of color blindness is red and green deficiency. The inability to see blue and yellow hues is far rarer, and will usually affect both sexes equally.
I have always assumed that someone who is colour blind only sees in shades of grey. The majority of people who are considered "colour blind" can actually still see colors, but certain tones will appear washed out or diluted and can be confused easily with other colors, depending on the colour vision deficiency type they they are diagnosed with.
If you develop colour vision problems when you have been able to see a full range of color, then an optician should be your first port of call. Sudden or gradual loss of vision in colour can indicate underlying health problems, such as cataracts.
An optician will conduct a test that will help ascertain the kind of colour deficiency you have.
The condition is caused when light-sensitive cells fail to respond appropriately to differentiations in light wavelengths that enable people to see a full spectrum of colour.
The photoreceptors number approximately 100 million in a human eye and it is the rods that are definitively incapable of perceiving color.
There are between 6 and 7 million cones in the human retina which are responsible for color vision, and these photoreceptors are concentrated in the macula. The center of the macula is called the fovea, measuring a tiny 0.3 mm diameter, this area contains the highest concentration of cones and is responsible for our most acute colour vision.
Inherited forms of colour vison deficiency are related to deficiencies in certain types of cones or the absence of them.
Asides from genetic makeup, other causes of colour defects or loss include:
- Parkinson's disease (PD)
Because it is a neurological disorder, light-sensitive nerve cells in the retina where processing occurs may be damaged and function abnormally. - Cataracts
Clouding of the eye's natural lens can "wash out" colour vision. Surgery can restore bright color vision when the damaged lens is replaced with an artificial intraocular one. - Tiagabine for epilepsy
This is an antiepileptic drug which has been shown to reduce color vision in approximately 41% of patients taking it, although the effects are not long term. - Leber's hereditary optic neuropathy (LHON)
Particularly reported among men, inherited optic neuropathy can affect carriers who don't show any other symptoms but do have a degree of color blindness. Red-green color vision defects primarily are noted with this condition. - Kallman's syndrome
Failure of the pituitary gland, can result in incomplete or unusual gender-related development eg. The sexual organs. Color blindness can be one symptom it.
Unfortunately the normal aging process will damage retinal cells. An injury or damage to areas of the brain where vision processing takes place also can cause color vision deficiencies.