Retinitis Pigmentosa (RP):

Retinitis Pigmentosa is actually a group of inherited diseases that affect the retina of the eye causing a degeneration of photoreceptor cells. These cells are what capture light enabling us to see. When these cells degenerate, patients experience loss of night vision, color vision and peripheral vision. Eventually tunnel vision may occur. While inherited, Retinitis Pigmentosa may skip generations and therefore is difficult to track. Any person who has a family member with a retinitis pigmentosa should immediately be tested by an eye care professional.

Typical reading solutions are desktop magnifiers.

Also See:
Macular Degeneration
Diabetic Retinopathy