There are a number of photochromic and light-adaptive lenses for use in different types/changing light. Nanotechnology has made increasingly better changes in that. (Here) is a look at different types/colors of lenses and uses.
If you're talking about really bright to quickly really dark then i just quickly pull my glasses off since i use chums on them and they'll just hang. I use a different type/colored lens depending on what the days ride light is going to be since it’s a quick and easy change with one pair of my riding glasses…Oakley's with prizm lenses are my most used and versatile ones for rides. For my eyes they work well for contrast and clarity in seeing road surface changes especially on days with a mix of cloudy and sunny skies and from sun to mountain shady treed sections especially on descents…. the downside is price but mine also are well made and fit me really well so they’re worth it for me. I also use gray lenses when in bright desert sun and yellow for dawn/dusk commutes. What works for me may not for you though so trying different colors/types is probably the best way to find something that works for you. Perhaps go to REI, lbs etc. and try some different ones.
eta..a work colleague and mountain biker said she really likes trail prizm's for the continual clarity going from light to shade and for seeing roots/rocks etc. on a trail.
Last edited by rebeccaC; 06-16-2016 at 05:24 PM.
‘The negative feelings we all have can be addictive…just as the positive…it’s up to
us to decide which ones we want to choose and feed”… Pema Chodron