It would be very useful for snipers as well. One thing they must always be cognizant of is how their optics might reflect the sun. Snipers will be safer if they don't have to worry about the enemy spotting their position due to reflections off their scope.
I distinctly remember that for the spy community, a way you find video recording bugs is by flashing light and looking for a return glare of the lens.
If these do not show the reflective glare, then the spy community has a really nice tool (and a problem to find).