Oddly enough, I've never dipped into the Air Gear fandom yet I still know where to get the eyepatch. A few J-rock websites carry them, I do believe, and if it's just a simple medical eyepatch then you could try your local pharmacy.
As for Komui's eyeglasses, he does balance them a bit farther down his nose than other people, so try going to, say, an Albertsons or a Dollar store and finding a pair of eyeglasses that look like his with very weak lenses. Weak lenses are better than either no lenses at all or just pieces of glass, because the no-lens method looks a bit odd and the glass method can take a while to clear with your eye doctor and can cost as much as getting a regular pair of glasses. Since Komui puts his glasses farther down his nose the very weak lenses shouldn't even bother you.
Things I'm working on: Mele: Juuken Sentai Gekiranger; Aguri Kusugami: GARO Yami o Terasu Mono
Cons I plan on attending:
Am I the only one who thinks just living is sad?