Color Vision Deficiency is a person's inability to distinguish certain shades of colors or, in more severe cases, any colors. The most common deficiency is with reds and greens, and less commonly blues and yellows. The inability to see any colors is rare and called Achromatopsia. The severity of a color deficiency can vary from mild to severe depending on its cause, and it can occur in two eyes or just one. If the deficiency is binocular it is most times an inherited trait; if it is monocular, it is likely due to an ocular injury or illness.
Within the retina, there are cells called cones, each with a light sensitive pigment that helps to distinguish colors. If there is an inherited or acquired defect with the cone, this can result in a color vision deficiency. Inherited color deficiencies are most often due to an X-linked gene passed from mother to son, and commonly result in a red-green deficiency color deficiency. Disease or damage to the optic nerve or retina can cause a color vision deficiency for the affected eye. Such diseases include diabetes, glaucoma, macular degeneration, Alzheimer's, Parkinson's, multiple sclerosis, leukemia, sickle cell anemia, and chronic alcoholism. Certain medications and chemical exposure can also cause color vision changes.
Treatment varies depending on the cause of the deficiency. For inherited color vision deficiencies, there is no cure. With illness or damage related deficiencies, treatment of the cause can improve color vision. The use of tinted glasses or contact lenses has been utilized to help an individual to more easily distinguish colors. Organizing and labeling belongings and remembering location and order of things, can help individuals compensate for his/her color vision deficiency. Although there can be some occupational limitation, a color vision deficiency is adaptable for most individuals with limited effect on vision and ocular health.
Diagnosis of a color deficiency is achieved through a comprehensive eye exam. Using specialized tests, a doctor can determine the presence, severity and type of color vision deficiency an individual has. With correct color recognition important in learning and development, a comprehensive eye exam is strongly recommended for children before school begins to identify any possible color vision deficiencies.