That is the first thought I had. The expectation here is that the blind need help, which may not be the case. The interesting thing to me was that the blind can "see" through echo location. Very cool stuff.
SOME blind people can see using echo location. From what I understand, children can learn faster in detecting objects with sound vs someone much older where it may take much longer. There is a pretty good Wiki on it that explains more and includes some people from the show[1].
20/250 vision is... really good. Able to use a full 80x24 terminal with ease. Able to drive as long as you're not too picky about legality or reading signs. Able to read facial expressions in a conversation. I'm very curious about the details of 'equivalent'.
Wow, yeah. I'm 20/400ish without my contacts in (nearsighted, -3.75/-4.0, plus some mild astigmatism), and while I couldn't drive a vehicle like that (or rather, wouldn't - I could probably stay in the lane okay during the day, but wouldn't be able to read any signs, and after dark the whole experience would be terrifying), I can certainly interact fine with others, read facial expressions as long as a person isn't on the complete other side of the room, can easily navigate unfamiliar rooms, and use a book or a screen as long as I hold it within a foot of my face.
With nearsightedness, you can have nearly normal vision 1 foot away even if you have much worse vision 20 feet away. With this system I suspect you can see things better when they're closer just because they encompass more of the visual field, but you probably can't see something 1 foot away nearly as well as a myopic person with 20/250 vision.
On the other hand, you might still be able to read. The vOICe people published a paper (http://www.sciencedirect.com/science/article/pii/S0896627312...) that shows that regions of the brain that are activated by letters/words in normal individuals and by Braille reading in the blind are activated by vOICe after training.
It's limited to 1 fps though. However I'm very impressed this is possible. I had a similar idea recently, and had no idea it had already been done or worked so well.
[1]http://en.wikipedia.org/wiki/Human_echolocation