Achromatopsia is a rare, autosomal recessive inherited retinal dystrophy that is known to be caused by at least 5 different genes. As its name implies, those affected have decreased or complete loss of color vision, as well as reduced central vision, photophobia and nystagmus (a constant roving movement of the eyes). These symptoms are present from infancy, though it is important to note that achromatopsia is a stationary disease and patients will typically not worsen with time. Achromatopsia can be classified into two types: “complete” and “incomplete”. In complete achromatopsia, there is a complete loss of colour vision, while in incomplete achromatopsia some colours may still be seen and visual symptoms in general may be less severe. Remember not all colour blind individuals have achromatopsia – many different types of inherited colour blindness affect a significant portion of the population (e.g. red-green colour blindness), but these are not in the spectrum of retinal dystrophies.
For more information please visit:
http://ghr.nlm.nih.gov/condition/achromatopsia