Lens is hard to change in and out and lens is big.
Review:
they are few key strengths and key weaknesses.
weaknesses
lens is wide and hard to change
strengths
light can't even tell it's on ( I know from experince)
I bought this mask off of a friend and he bpught it from a sporting good store for $30 i bought it off him for 10 or 20 $ it was well worth it
Conclusion:
Don't spend more than $30 on one can buy them new for that much
Wouldn't you want a big lens so you can see more and have a bigger field of vision? "The efficiently bigger the lens is the better" is the general consensus, I think.