Excessive sensitivity to light with the sensation of discomfort or pain in the eyes due to exposure to bright light.

Inability to see well at night or in poor light.

A form of macular degeneration characterized by the presence of multiple cysts in the macula.

Difficulty with discriminating red and green hues.

Tritanopia is an autosomal dominant disorder of human vision characterized by a selective deficiency of blue spectral sensitivity (Weitz et al., 1992).

Diminished clarity of vision.

An absolute or relative decrease in retinal sensitivity extending from edge (periphery) of the visual field in a concentric pattern. The visual field is the area that is perceived simultaneously by a fixating eye.

A nuclear cataract is an opacity or clouding that develops in the lens nucleus. That is, a nuclear cataract is one that is located in the center of the lens. The nucleus tends to darken changing from clear to yellow and sometimes brown.

A type of cataract affecting the posterior pole of lens immediately adjacent to ('beneath') the Lens capsule.

Absence of the combined rod-and-cone response on electroretinogram.

An inherited retinal disease subtype in which the rod photoreceptors appear to be more severely affected than the cone photoreceptors. Typical presentation is with nyctalopia (due to rod dysfunction) followed by loss of mid-peripheral field of vision, which gradually extends and leaves many patients with a small central island of vision due to the preservation of macular cones.

An abnormality of the retina characterized by pigment deposition. It is typically associated with migration and proliferation of macrophages or retinal pigment epithelial cells into the retina; melanin from these cells causes the pigmentary changes. Pigmentary retinopathy is a common final pathway of many retinal conditions and is often associated with visual loss.