Normal vision. Courtesy NIH National Eye Institute

The same view with tunnel vision from retinitis pigmentosa. The blackness surrounding the central image does not indicate darkness, but rather a lack of perceived visual information. Retinitis pigmentosa, or RP, is a group of genetic eye conditions. In the progression of symptoms for RP, night blindness generally precedes tunnel vision by years or even decades. Many people with RP do not become legally blind until their 40s or 50s and retain some sight all their life. Others go completely blind from RP, in some cases as early as childhood. Progression of RP is different in each case. RP is a group of inherited disorders in which abnormalities of the photoreceptors (rods and cones) or the retinal pigment epithelium (RPE) of the retina lead to progressive visual loss. Affected individuals first experience defective dark adaptation or nyctalopia (night blindness), followed by constriction of the peripheral visual field and, eventually, loss of central vision late in the course of the disease.