This is probably caused by calcification of Bruch's membrane. If the calcifications continue, the membrane may develop cracks, which are called angioid streaks. Angioid streaks are the most diagnostic feature of PXE in the eye. The cracks may eventually allow bleeding to occur through them. If bleeding occurs in the area of the macula then central vision will deteriorate.
Central vision is the vision used for reading, driving, and all tasks requiring acute vision.
Although PXE can cause loss of central vision, peripheral vision is usually unaffected. When central vision loss reaches a certain level a person may be declared legally blind, but it would be very uncommon for a person with PXE to become totally blind. The incidence of vision impairment is not known. This is an area of controversy. Laser surgery is not usually done close to the macula.