Deuteranomalia

Deuteranomalia is a form of anomalous trichromacy, a type of red-green color vision deficiency. It is the most common type of red-green color blindness, affecting approximately 6% of males and 0.36% of females. Individuals with deuteranomalia have a green cone photoreceptor that is shifted towards red wavelengths. This means they are less sensitive to green light than a person with normal color vision. As a result, they have difficulty distinguishing between certain shades of red and green, especially when the colors are muted or when there is poor illumination.

The condition is genetic and inherited in an X-linked recessive manner. This means that the gene responsible for the green cone opsin is located on the X chromosome. Males, having only one X chromosome, are more likely to be affected if they inherit the altered gene. Females, with two X chromosomes, are usually carriers and do not exhibit symptoms unless they inherit the altered gene on both X chromosomes, which is rare.

Deuteranomalia does not typically cause significant visual impairment; individuals can usually see and function normally in most aspects of daily life. However, it can pose challenges in certain professions or activities that rely heavily on precise color discrimination, such as piloting, certain art or design fields, or identifying warning lights. Diagnosis is usually made through various color vision tests, such as the Ishihara plates or the Farnsworth D-15 test. There is no cure for deuteranomalia, but specialized glasses or contact lenses can sometimes help improve color discrimination for some individuals.