Hello, a small 64x64 map I'm making requires that every player (players are marines) be blinded with optical flare... but the only way I can think of, is to move the marine next to an enemy comp medic, thus attacking it, said medic will then *use* optical flare, to "defend" itself.
Is there an easier way to do it?

nope. Check both DLDBes for blind concept maps. I know there's one by kenoli with ghosts and blind observers.

Computer controlled medics will pretty much blind any nearby enemy unit that has over 80 hp.
They'll do it immediately if they're being attacked by something, which doesn't necessarily need to be the unit you want blinded.