In my case, tech would not be much help. My left eye was poorly developed. It looks mostly normal except that it's an obvious lazy eye. The insides of it are a mess, though. The lens is misshapen and unable to focus, and about 20 years ago, I had a histoplasmosis episode that killed about half the retina, leaving that eye incapable of perceiving anything.

Best wishes to your sister. I had a co-worker years ago that was gradually losing his eyesight and hearing. He was headed towards being completely deaf & blind. I know he worked with a group called the Chicago Lighthouse for the Blind that set him up to learn Braille, and they also assisted him in running his own business, a snack bar that operated inside the place where I worked.