I ordered my sun glasses with ImpactRX FreeForm TEK Photochromic Green lenses ($420 for the lenses and $100 coating). They just don't work - they stay dark all the time! To be fair, the prescription is very comfortable and the lenses are very clear, but the photochromic feature was disappointing.
I use these lenses for squash. They have been fantastic. Besides the obvious improvement in my vision the glare reduction and anti-fog have been superb. The service and delivery time were excellent too.