Well, how do we define "legally blind"? Is that with or without glasses and other adaptations.

My eyes are so bad that in 15-20 years I'll probably be legally blind without my glasses. Will we deny that right to someone who with the use of adaptive technology can function as a normal member of society? Or those who have 90% the functionality of a fully sighted person, even though they can still drive? 80%? 70%? 60%?

A person with a prosthetic limb is still handicapped under the law, even if they use their new leg to run a marathon. And when ocular implants become available, what then? The big delays to getting "cyber eyes" on the market are the FDA and our understanding of neurology- the working parts of a digital camera, less the zoom mechanism, can be made about the size of an eyeball already. At that size it isn't great, but you can see well enough that it works as legal evidence. A large fiber optic front sight with a tritium bead at the front so it is always brighter than ambient light can be seen would just glow in that type of sensor. And mounted on something like a j-frame or a pocket pistol is suitable enough to self defense.

No, I don't think the law should deny them the right. That sets up a slippery slope. However, I would say that common sense says that if you can't see your hand in front of your face, you shouldn't carry.