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Achromatopsia: Definition

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Achromatopsia

Achromatopsia refers to agnosia for colour. This term includes colour blindness. A partial or total absence of colour vision is the hallmark of achromatopsia. People with complete achromatopsia cannot perceive any colours; they see only black, white, and shades of grey. Incomplete achromatopsia is milder; it allows some colour discrimination. Other vision difficulties associated with achromatopsia include increased sensitivity to light and glare (photophobia), involuntary back-and-forth eye movements (nystagmus), and severely decreased visual acuity. 

Farsightedness (hyperopia) or, less typically, nearsightedness (myopia) might affect those who are affected (myopia). During the first several months of life, these eyesight issues first appear. Achromatopsia differs from the more common forms of colour vision deficiency (also called colour blindness). People can perceive colour but have difficulty distinguishing between certain colours, such as red and green. 

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