Typical symptoms of RP are what are commonly referred to as "night blindness" and "tunnel vision". Night blindness refers to a reduced ability to see at night time, but more than that it entails a diminishing ability to see in dimly lit conditions generally, as well as in judging changes in level such as steps and gutters. Adjustments to changes in light intensity are typically slower and sensitivity to glare greater than is the case with the normal, healthy eye. All this results from the eye having fewer and fewer photoreceptor cells with which to transmit visual images to the brain.
The common pattern with RP is for photoreceptor cells to be lost progressively from the outer edges of the retina. This causes a progressive loss of peripheral vision, meaning side, upper and lower vision. It is as if the affected individual is viewing the world through a narrowing tunnel. Unlike a person with a normal field of vision, the person with tunnel vision cannot simultaneously look ahead and downwards or sideways without using a scanning technique by moving the eyes. However, the central vision of the person with RP may remain largely unaffected for a considerable number of years, enabling the individual to continue to read, watch television and perform other visually detailed tasks.
It is important to understand that with RP there is no uniform age of onset of symptoms and no uniform rate and extent of vision loss. These can vary markedly from individual to individual and are not usually able to be predicted.