This publicity shot shows the difference between an ordinary non-coated lens (left) and a coated one (right).
The advantage of coateds is that they're more efficient because they let more light through without reflecting some of it away, plus of course light won't glint off them giving away your position whether you're out and about in the woods, or whether you're peeping out your window or whatever, day or night.
But nature got there first..
- WIKI- "-Moths' eyes have an unusual property: their surfaces are covered with a natural nanostructured film which eliminates reflections. This allows the moth to see well in the dark, without reflections to give its location away to predators.
An antireflective or anti-reflection (AR) coating is a type of optical coating applied to the surface of lenses and other optical devices to reduce reflection. This improves the efficiency of the system since less light is lost"
http://en.wikipedia.org/wiki/Anti-reflective_coating
