Slowly she's been losing the rest of her sight because her eye has no way to control the light that comes through. That has damaged her cornea.
Now she's taking part in a first of its kind experiment in Scotland where scientists are trying to restore some of her sight. Doctors transplanted stem cells into her eye that they hope will protect her cornea and repair the damage.
Scientists in the lab isolate the cells from donors, then grow them into tissue.
Professor Bal Dhillon, one of the researchers says, "they do exactly what they do in life, and they reproduce themselves and they produce more mature cells and so they grow out over the surface."
Until now, a full cornea tissue transplant was the only treatment.
"I think it will be a major step forward for the many hundreds and thousands of individuals," says Dr. Ashish Agrawal, who's also involved in the study.
Sylvia has no regrets about having the experimental treatment, saying "I feel extremely excited and so honored to have the opportunity."
It will be months before doctors know if the procedure helped Sylvia.