I wear glasses in my day-to-day life. While I've often used contacts while cosplaying, I've often just worn glasses and popped them off for photographs. Figuring out where to put them is another issue altogether.
As a brief PSA, if you see a cosplayer with their hands full and want to take their picture, maybe ask for it later. Or if you need to catch it right then, at least give them time to get their stuff settled.
For the entire run, please visit www.CosPainComic.com!