Why is Anti-reflective coating applied to the back surface of sunglass lenses?

[Nisswa]

I always thought the anti-reflective coating is applied on the front surface, but I was wrong. So why is Anti-reflective coating applied to the back surface of sunglass lenses?

[Niter]

AR coating is applied only to the back surface of sunglass lenses because there are no cosmetic or visual benefits to eliminating reflections from the front surface of dark-tinted lenses. It eliminates glare from sunlight reflecting into your eyes from the back surface of tinted lenses when the sun is behind you.

[Nitro]

An anti-reflective coating on the back surface of sunglass lenses is used to eliminate the reflections of objects behind the wearer so that it can reduce reflections of light that come from behind you and bounce off into your eyes.