How quickly does it progress?
Although the appearance of the retina undergoes marked changes with age, vision usually remains fairly stable through young adult life. Long term visual prognosis remains to be defined. Visual acuity in patients with LCA is usually limited to the level of counting fingers or detecting hand motions or bright lights. Some patients are also extremely sensitive to light (photophobia). Patients with remaining vision are often extremely farsighted.
By the age of 20 most deaf people will be in training or already employed. Those who have RP may well be doing work which will eventually prove difficult or even dangerous to carry out. The rate at which vision will degenerate over the third decade of life is difficult to predict, there is therefore a question about when to change course. Should the keen young motor mechanic and student nurse carry on, and have perhaps 10 to 15 satisfying years of work, or should they change to something that they can work at even when their vision has become severely restricted?