I know what you mean I am dang near legally blind without my glasses. There are sports glasses you can buy from your eye doctor that work real well, I used to use them or you can get contacts which work alot better.
Since I ran out of contacts I have been fighting more and more without my glasses and although everything is blurry it is allowing my other senses to become stronger and reactions to become quicker and sharper.
I trained with this one black belt who was blind and it gave me a whole new insight on the beauty of what God has created, when one thing is taken away from us our body naturally begins to cover up for what's missing.
With BJJ you don't need to be able to see anyway, because it's close range combat you go off of the feel of the opponent and his body positioning to yours. TDK is a kicking art that if your reaction isn't quick enough then you will get knocked out with a kick to the head.
Both are great sport martial arts, but have their limitations on the streets especially if you have a vision impairment or poor eyesight without glasses. I would suggest an all around art where you can fight in close if you loose your glasses or strike to eliminate the threat before you loose your glasses, like Kenpo, Kajukenbo, penjat salat, kali, or one of those and they're fun to.
Martial Arts researcher, historian and technician. Trained in Martial Arts for 24 years.