I am the mom to Gavin Stevens (age 4), who is blind, and was recently shown on a video walking down a curb for the first time. AMA
I took the video, not knowing it would receive the attention it has. It has been a great platform for raising awareness of LCA. There are only 150 people in the USA with Gavin's gene mutation, that has caused him to be completely blind. He is a happy and healthy boy, and we will answer any questions you may have (Gavin too)!
Gavin's very rare condition (LCA) inspired us to start a non-profit, and we are close to funding a research lab, to hopefully bring treatment to Gavin, and many others. It is an inherited retina disease, and he is the first case in our family to be born blind.
EDIT: I'd be happy to continue answering your questions tomorrow (Wednesday) morning.