Colorblindness is usually an inherited condition that is x-linked recessive. As a result, very few women are colorblind, but approximately 1 in 10 men has some degree of colorblindness. There are also some forms of colorblindness that can be acquired after birth. The most common of these is caused by a rheumatoid arthritis drug called hydroxychloroquine (Plaquenil). The most common type of colorblindness is red-green, but there is a wide range of variability within this group, from very mild to extreme. The second most common form is blue-yellow, and a red-green deficit is almost always associated with this form. The most severe form of colorblindness is achromatopsia, the inability to see any color. It is often associated with other problems such as amblyopia (lazy eye), nystagmus (small, jerky eye movements), severe light sensitivity, and extremely poor vision.
| 
