File:Coatedlens.jpg

The glass lens with anti-reflective coating on the right shows an obvious decrease in the amount of light reflected onto the wall vs. the uncoated plastic lens in the center and the uncoated glass lens on the left. Because of the sharp angle of light on the lens, the effect is much greater than when light enters the lens at a 90-degree angle.

Picture by BLF user relic38 from this post and is used with permission.