Color blindness refers to an anomaly in color vision wherein individuals experience difficulty in differentiating between specific colors.
The most prevalent form of color vision deficiency involves a diminished ability to distinguish between red and green hues. In most cases, red-green color vision deficiency arises from abnormalities in the light-sensitive cells of the retina. These abnormalities are typically hereditary and often linked to the sex chromosomes (as seen in genetic disorders). Males are primarily affected, while females are generally unaffected but can carry and pass on the condition to their offspring. On rare occasions, defects in color vision can be acquired due to retinal or optic nerve diseases or as a result of physical trauma. There are two variations of red-green deficiency. Individuals with a severe deficiency in perceiving green struggle to differentiate between oranges, greens, browns, and pale reds. Severe red deficiency, on the other hand, causes all shades of red to appear muted or dull.
There is a significantly less common type of color vision deficiency in which individuals are unable to distinguish the color blue. This condition can be either inherited or caused by the degeneration of the retina or the optic nerve. Additionally, a condition known as monochromatism, characterized by the complete absence of color vision, does exist but is exceptionally rare.