Hey Rich,

You can't beat mil spec for durability! I'm the first to admit the cheaper stuff wears out in a year or two -- the thing is, I almost always lose sunglasses in that time (hence my preference to buy cheap).

The enhanced penetration protection is definitely a feature worth extra $$$. Sounds like you got a great deal on a great pair of lenses. Hope you enjoy them (and your newly enhanced vision)! Isn't it great getting your vision back (and, in my case, much improved)?