From the day Christian Guardino was born, his mother, Elizabeth, knew that something was wrong with his eyes. They would jiggle and jerk and roll up into his head. One eye turned inward. When she fed him, instead of gazing up at her, Christian would stare at the brightest light around—a lamp if they were indoors, the sun if they were out. It was unsettling.
The first eye doctor who saw Christian grimly referred the family to a specialist at New York’s Mount Sinai Hospital. The specialist performed an electroretinogram (ERG), a procedure in which a tiny electronic sensor placed on the eye measures the retina’s response to bursts of light. A healthy retina will respond by firing an electrical signal down the optic nerve that produces, on the ERG machine’s printout, a deep valley followed by a tall peak. Christian’s ERG produced no such thing: only squiggles, ill-formed and weak.
Christian, the doctor told Elizabeth, had a retinal disease called Leber congenital amaurosis (LCA). His vision, already bad, would never significantly improve. Nothing could be done. The boy would see little of the world and would always walk, once he learned how, with a cane.