Achromatopsia

Achromatopsia is a type of cone dystrophy where there are normally problems only with vision from cone photoreceptors, the ones responsible for color and day vision and visual acuity.

Therefore individuals mainly see by their rod cells, may be completely colorblind or almost colorblind, and have poor visual acuity. They also may have a variable degree of nystagmus (involuntary movement of the eyes). Other types of cone dystrophies may involve some degree of loss of rod cell vision.