Okay, had a few seconds to play around with it...
1) Acuity (at least in U.S.) is usually measured in feet. You can choose the distance in feet, but acuity is in meters. 20/20, 20/25, 20/30 etc. would be useful. Would also be useful to have whole/half a chart.
2) "shortsighted" and "longsighted" test is basically useless. Science behind makes sense, but as a quick test, not useful.
3) Color vision is cool, although brightness of lcd screen can vary.
4) Amsler grid for macular degeneration is not centered.
5) I cannot find near reading test...maybe have to look some more.
Just initial impressions - cool that you guys are working on this, and I do understand that in France things are different than U.S. Thanks!