Originally Posted by Lucyfur

If by "wrong measured" you mean "the wrong size" yes, it will cause damage. If they're too small they can compress your corneas and leave them misshapen or, worst case scenario, deprive your corneas of oxygen. If they're too big, they'll slide around your eyes. That's not really "harmful" per se, but it's not fun. I suppose they could scratch your cornea as they slide around, but I don't think that's very likely.

Why would you want to wear the wrong size contact lenses anyway? I hope you're not actually doing that. It's easy to get fitted properly.