Originally Posted by Logun
They look like something you would use doing a bit of welding
I can tell you, flying over a high overcast is just as bad (not that I've welded anything..). These work a treat; I bought 5 pairs: navbag, 2xcars, mowing and the boat!
The cost there appears to be $119 for the tri-focal lens and frames can run USD $150 -$200
Frames for trifocals? Cheap as chips here. Any "normal" frame will do. Plenty of space for the three zones.