An estimated 285 million people (worldwide) have some blindness or visual impairment. About 43% of those visually impaired around the world are people who need glasses but don't have them. However, there are obviously blind people who have more severe vision problems that are more technologically difficult to fix. Some kids with blindness are learning how to echolocate
nowadays, but that's a skill that gets harder to learn as a person ages. Here are just a few other ways that might restore vision to people someday.
If you'd like to read more awesome and interesting stuff, check out this unrelated (but not entirely random!) Techdirt post