It all depends on how you train, KungLE, but in my oppinion glasses and grappling arts don't mix - at least not during sparring. Sooner or later your glasses will be crushed beyond recognition under you and your opponent. Furthermore - if you train full contact using head gear you need to have a special helmet that allows you to wear glasses.
In regard to your question if you are in trouble if you get your glasses knocked off during a real fight - I know I am. I have a really poor eyesight and many times I have tried sparring without any glasses or contact lenses. I have noticed that I am in really big trouble when fighting from the distance (even against people with very little martial arts experience). I have noticed that I get hyper sensitive because everything is just a blur. If my opponent fakes a blow or kick I always fall for it. I don't have any feel for the distance between me and my opponent(s) and I can't time my attacks or my defense. My only chance is to close the distance and get within "hugging-distance" - that way I stand a better chance of protecting myself as well as striking back using fists, elbows or knees or to take the fight to the ground. The problem is of course that I risk being hit on the way in because I can't see properly. Something I have noticed is that when in in-fight I have a hard time using head butts when I'm not wearing glasses. We always use helmets so there is no risk of injury but my brain often refuses because my eye sight is so poor. Very annoying.
So - if you plan to take up a martial art that involved grappling or full contact sparring then I would advice you to get some contacts. Never the less - No matter what martial art you practise I advice you to try to fight without your glasses numerous times. At least until you get a feeling for what kind of problems you might have.
Best regards
Thomas
In regard to your question if you are in trouble if you get your glasses knocked off during a real fight - I know I am. I have a really poor eyesight and many times I have tried sparring without any glasses or contact lenses. I have noticed that I am in really big trouble when fighting from the distance (even against people with very little martial arts experience). I have noticed that I get hyper sensitive because everything is just a blur. If my opponent fakes a blow or kick I always fall for it. I don't have any feel for the distance between me and my opponent(s) and I can't time my attacks or my defense. My only chance is to close the distance and get within "hugging-distance" - that way I stand a better chance of protecting myself as well as striking back using fists, elbows or knees or to take the fight to the ground. The problem is of course that I risk being hit on the way in because I can't see properly. Something I have noticed is that when in in-fight I have a hard time using head butts when I'm not wearing glasses. We always use helmets so there is no risk of injury but my brain often refuses because my eye sight is so poor. Very annoying.
So - if you plan to take up a martial art that involved grappling or full contact sparring then I would advice you to get some contacts. Never the less - No matter what martial art you practise I advice you to try to fight without your glasses numerous times. At least until you get a feeling for what kind of problems you might have.
Best regards
Thomas