There are no vision tests to buy a gun, get a permit, or own it -- unlike driving.
There are many people who are legally blind without their corrective lenses.
It's foreseeable (pun) that one of those people who by law must only operate a vehicle with corrective lenses may have to operate a firearm without them. If during a struggle their glasses are knocked off and broken, or in the middle of the night they can't locate their glasses before defending against someone coming through the bedroom door, they may be legally blind but in need of using a firearm. Training would be easier, but in actual SD/HD scenarios, that might not be equivalent.
Unless there's a minimum standard set for seeing, hearing, or whatever other physical limitations people have, the Second Amendment applies to them as with anyone else.