31 not to late to start. I'm 31 and i started shotokan karate-do in september. i have glasses and i just wear them like when i need to see the blackboard or overhead in university classes. I leave them home when doing shotokan and it doesn't affect my training. Couple weeks back there was a full page spread in our provincial newspaper (Im from NL, Canada) about a guy who started shotokan at 73 and got his black belt at the age of 80. I kept the article. Its not age that's important in martial arts. or whether you have glasses or not.