Sunglasses delimma

[zoom-zoom]

I have photochromic prescription lenses...I like them for wearing under any lighting conditions, as they go from REALLY clear to REALLY dark...but it takes probably at least 30 minutes for them to go from dark to clear. I've had faster ones, but they didn't have such a wide light/dark range.

I'm not sure there is a good eyewear solution for the scenarios you're describing, unfortunately.

[rebeccaC]

I have photochromic prescription lenses...I like them for wearing under any lighting conditions, as they go from REALLY clear to REALLY dark...but it takes probably at least 30 minutes for them to go from dark to clear. I've had faster ones, but they didn't have such a wide light/dark range.

I'm not sure there is a good eyewear solution for the scenarios you're describing, unfortunately.

If someone doesn't have a lot of eye sensitivity to light they should be able to find a transition range that works quickly for sun to shade. My eyes aren’t light sensitive so my usual riding lenses don’t go to completely dark nor clear either and I don’t notice any time lapse in clarity in the average type of temperature, sun and shade on my rides…with the exception of strong desert sunlight riding where I switch to darker lenses.....but yes if the lens is really dark from bright light going into a really dark area the best way is probably using a sunglasses retainer strap like chum etc. so you can just quickly pull them off and get your hand back on the handlebar.

Work on molecule chemical reaction is continuing to give faster transitions and longer life for plastic photochromic lenses. Depending on how the plastic, dyes and molecular engineering are done and the transition range it can take from instantly (more expensive to create) to seconds or to minutes to make a change. Hot/cold temperatures also factor in. Glass photochromic lenses can take much longer to change because of the silver halide crystals....plastic photochromatic with cheaper and easier to use naphthopyran molecules too.