quite a lot of states give restricted licenses to the legally blind. Not totally, legally.
They still have to have 20/60 or better with the visual aid and some of the states that initially allowed it reconsidered when they noticed the rate of accidents was much higher because of the lower reaction time with a visual aid. Some states also require 20/100, Wyoming, for example. 20/70 - 20/200 is considered low vision so after correction with a bioptic, or in states like Wyoming, you can drive with an acuity that falls into the range of low vision, not legally blind.
Article on KY law