Actually, from what I gather from my Stage 1 Physics course, you can only see lasers in the atmosphere because the light gets scattered by the atmosphere. So in space, unless you get 'hit' directly with a laser, you'll have no idea it's there.
you should have kept going in physics, enough to realize that lasers that are meant to do damage are on a wavelength of light invisible to the eye anyways. they might have a trace laser for targeting, but that'd be about it.