Eyeglass wearers are most familiar with Transitions. There are other photochromic lenses, made by Carl Zeiss, Vision-Ease, Rodenstock, Corning, Signet Armorlite. The quality of a photochromic lens is judged by how quickly the molecules on the lens activate, turning the lens darker or lighter based on the ultraviolet input; and in how dark they get; and in how long the photochromic qualities last.

There are three goggles in the market now that I know of that are photochromic: the Zoggs Predator Flex Reactor; the HUUB Aphotic (pictured above), and a photochromic version of the TYR Special Ops 2.0. I have not tried the TYR. I have no idea what the lens quality is like. It is what seems to me an unreasonably inexpensive goggle for a photochromic. The photochromic lens in the TYR Ops 2.0 seems to cost only $3 to $6 more than the polarized lens in that same goggle. This makes no sense, and gives me pause when considering the lens quality, but since I have not tried this goggle I cannot report on it.

I have extensive experience with the two other goggles, and I can talk about them.

Both the Aphotic and the Predator are very gently smoked. I have used the Predator in indoor pools and these goggles are fine. I've also used both these goggles on bright, sunny days outdoor and they're also both fine. I'm happy with the photochromic quality of each goggle's lens.

The Aphotic's lens is much more curved than the Predator. You can't really tell until you look at this goggle compared to the Predator at various angles. This makes the Aphotic both a goggle with a wider field of vision than the Predator, and it makes the goggle a bit more "distortive," if that's the word. I have never found a curved goggle lens that does not have some sort of distortion – even from companies like Aqua Sphere that have curved lenses down to a science.

Indeed, the Aphotic is the goggle you'll want if what interests you is a photochromic lens in the larger, wider-vision, semi-mask motif that has made Aqua Sphere so popular. Until Aqua Sphere gets around to putting a photocrhomic lens into the Kayenne, the Aphotic is as close as you are going to come.

The Aphotic is just a bigger goggle than the Predator. It's further away from your face. A bigger "footprint" on your face (is that a faceprint?). I notice this when I push off the wall. For this reason, and especially for pool swimming, I prefer the Predator. It's just a little bit more minimal although wearers of Swedes would scoff at the idea that either of these goggles is minimal.