The medical name for this congenital disease is "retinocerebral angiomatosis". It is characterized by the development of blood vessel tumors in the retina of the eye and in the brain; lesions and cysts can also develop in the spinal cord, pancreas, kidneys, and other organs.
From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.