Ocular albinism (OA) results from the inability of the normal pigment cells in the eyes (especially the iris and the retinal pigment epithelium) to produce normal amounts of pigment. Exactly how the reduced amount of pigment leads to reduced visual acuity (aka eyesight), nystagmus (aka involuntary rapid movement of the eye), and sensitivity to sunlight is not yet clear, nor is it necessarily true that the pigment itself is primarily responsible, but rather some other developmental pathway in the assembly line of the eye and of visual development.