Poor Color Vision or most people refer it to as Color blindness, is the inability of the eye to see certain colors. Unlike true color blindness, wherein everything is in shades of black and white, a person with poor color vision can still see some of the colors. It is the result of lacking one or more light-sensitive chemicals so instead of 3, they only see two of the primary colors.
Poor color vision has several causes, including:
- Inherited disorder. It is more common to men than women. The most common color deficiency is red-green. Blue-yellow deficiency is much less common.
- Disease. Sickle cell anemia, diabetes, macular degeneration, Alzheimer’s disease, glaucoma, Parkinson’s disease, chronic alcoholism and leukemia can cause poor color vision.
- Certain Medications. Some medications can alter color vision. Examples of this drugs are used to treat heart problems, high blood pressure, erectile dysfunction, infections, nervous disorders and psychological problems.
- Aging. The ability to see colors may be weaken by old age.
- Chemicals. Exposure to some chemicals in the workplace, such as carbon disulfide and fertilizers, may cause loss of color vision.
People affected by poor color vision may not be able to distinguish:
- Different shades of red and green
- Different shades of blue and yellow
- Any colors
Defects can be mild, moderate or severe.
Screening tests are used to diagnose inherited color vision deficiency. Examples of this are:
- Hardy-Rand-Rittler (H-R-R) and Ishihara Color Plates . The person will be asked to identify colored shapes or numbers that lie within a jumble of dots. Depending on the person’s response, the physician will evaluate the type and degree of color deficiency.
- D–15 and the Farnsworth-Munsell 100-hue disk-matching test. This test assess the ability of the person to identify gradations of clor by placing discs in order.
Inherited color vision deficiency has no cure. People with this kind of condition enable to create their own system of recognizing colors as they grow. There are specialized glasses and tinted lenses that normalize colors. However, this lenses won’t improve your ability to see all colors.
Acquired color vision deficiency requires treatment of the underlying medical problem. In most cases, normal vision returns after the underlying has been treated.