If glasses had genders, you could say that they have many. Transition lens are built different from boring, clear, single state lens; cis-glasses. They are arguably gender fluid, transitioning between a spectrum of clear and dark… And in this photo, they’re trans glasses; trans as a root word means “across, beyond, or opposite from”, as the lens goes from clear to dark, or one lens being different from the other. The same even goes for fats. Transfat refers to the Hydrogen double-bond of a fat molecule being on different sides, whereas cisfat’s double-bond is on the same side.
Anyways, I have had my first ever pair of transition glasses for a couple of years, and I think they’re great. Normal transition glasses darken upon ‘seeing’ UV light, and they reveal just how much UV light gets through even the thickest of clouds. Unfortunately, they don’t darken behind modern car windows, as car windows block UV rays from penetrating, which is reassuring to know you won’t get sunburn in a car. There is a higher up, though: Transitions “XTRActive” (or PhotoMax transitions) reacts to intense visible light. They’re pricier than normal transitions, but if you’re going to pony up for transitions to begin with, why not pay a bit extra for the higherup transitions?