I’ve got a new route that goes through some deep forested paths intersected by wide open roadway bike lanes, alternating from bright sun to deep shade several times in quick transition. The forested paths especially require sharp vision. I’ve tried Oakley Prizm Road, my Serengeti drivers glasses and cheap Eagle Eyes. The Eagle Eyes do best in forest but are blinding when you hit the open areas. The Prizm Road is too dark in the forest. The Serengeti is the best of the 3 as it offers decent clarity in the forest and blocks the sun well.

Taking the Serengeti drivers lens as the benchmark, I’d like to boost the forest performance slightly and keep the sun block

Swapping lenses between the transitions is not practical

moscot flips might do the job?

......better yet: https://www.amazon.com/Nightvision-B.../dp/B07N97WQ2V

One word: Photo-chromatic

Yea. I like those.

Wonder how long before I break the flip mechanism though. Not cheap.

I had the same issue many times. I bought a pair of clear Goodr glasses. Maybe you can keep this pair with you when you know you are
going through foresty areas. They are basically a shield against bugs and debris you get from the wind. I found them invaluable.

https://goodr.ca/products/modern-day...SABEgKQrvD_BwE

The Serengeti and Smith I also own are Photo-chromatic. Maybe because I’m in and out quickly and the transition is extreme but I don’t feel like they realize their potential. Either the bright is too bright or more common with both, the dark is too dark.

A few trails in Phoenix go through tunnels under roads and those are tough. I just slow down a bit so I have time to avoid anyone that might be on the wrong side of the trail in the tunnels.

maybe something like one of the that goes from light to med tint vs med to dark?

I have have pair and like them

that said, my similar situation is going from bright to dark shade when going under a bridge on a MUP.....the change is not instant but not having super dark to start helps

not sure there is a perfect solution


https://tifosioptics.com/collections...8-1297744a7d1a

I've got a similar situation where a local MUP goes through a tunnel goes under a wide roadway. The roadway was rebuilt to make it wider with more lanes and it also included adding lights in the tunnel. It doesn't help that much during the day when the sun is out and the light/dark transition is extreme so I just slow down when approaching it. Even at a slow speed your eyes don't have time to adjust, you just have to be very intent on watching for silhouettes of other bicycle riders or people walking/jogging through the tunnel.

I’ve had a few photochromatic sunglasses.

They are much slower to lighten up than darken.

They’re decent and I wear my Wildhorn glasses most days. Good bang for the buck.

With rapidly changing lighting, there’s no glasses that I know of that can keep up. Most I know of change based off UV light, rather than sheer brightness, mine are pretty dark even with moderate sunlight. They’re cool glasses but they really only excel on rides that finish in fading light.

For tunnels and dark spots, you’re probably better off taking your glasses off for a minute. Some fit well in pockets, some in helmet vents. Figure out what works best for your setup.

May try Prizm Trail. Apparently the trail version will give better low light than Prizm Road but likely at the expense of full sun protection.

If that don’t work, the Serengeti Drivers are not horrible.

I have that issue here on some routes I ride. Particularly the 11 mile long MUP. It's especially bad when going through the sections where it's like rapid fire sequences of extremely bright and extremely shadowed. One day I was crossing over the sunny crest of a small rise and in the dark shadowed dip in the trail, a guy had decided to do pushups crosswise to the trail and right in the middle!

Thankfully, I was able to see him soon enough. I use lightly tinted glasses for such days in those conditions. But with my eyes getting older, they don't seem to adjust from light to dark as fast as they once did. So I see that as a issue more so than what type of sunglasses I should wear.

If you aren't worried about the glasses being "wrap around", you could get an inexpensive pair of glasses with clear, or slightly tinted lenses (no rx-just clear), and get a pair of clip on sunglasses which can be flipped up or down.

Becomes a real issue for me especially late fall to early spring, when the sun is lower and often shines directly into my eyes. My new helmet has a fabric visor that velcros to the front and can be quickly flipped up and down in response to the sun, as needed. Helpful and low-tech.

I don't find photochromatic lenses fast enough to respond to dappled shade that creates a strobing effect; they can be effective for continuous stretches of direct sun and deep shade, though. Shopping about, mountaineering glasses seen to offer the greatest range and darkest tints. Uvex is one brand.

Temporary solution; no helmet, sunglasses on a lanyard.

not ideal but vision trumps helmet

hoping the Prizm Trail do better. Ordered.

i could never find photochromatic shades that went from a mildly dark to very dark tint in a style/fit that I like.... not willing to pay a mortgage payment price, as I know that tends to open up options..

‘Vision trumps helmet”.

About a billion years ago, popular sunglasses were the Vaurnets. Tops and bottoms were very dark. Middle not so. (And their famous trademark mirrowing that likewise varied with height.) My favorite glasses for sailboat racing as they blocked sunlight and light reflected off the water very well but I see everything on deck just fine. Great for looking into the sun to watch the edge of the spinnaker for trim for maybe and hour or more at a time. Also so I would not kill myself when I went below. I didn't like the road blocking for bike riding but it seems to me a modification of this concept could allow good vision both riding into and out of light simply by adjusting one's head tilt. I don't know if this has ever been done but I might ask about custom shading next time I go for sunglasses..

For bike riding I rarely do tint, just clear lenses with UVA/UVB treatment.

what would one do if no helmet is used, but they are running tubeless on a steel framed rim braked 13 speed roadie?

They could coat their lenses in carbon grease.

Oh you are making my head hurt. Sounds like a future forum discussion which will go six pages initiated by Larry, but will have to add shirtless with on helmet.

Oh, and I believe the type of sunglasses the OP is looking for - instant changing for light conditions, is made by a company called, Panacea.

I think you'd have to be riding very slowly for photochromic lenses to help O.P.

Riding some of the bike paths around Tucson, my Rudy Project photochromics would let me see at the end of the tunnels, but while riding the beginning of an underpass (occasionally with a turn at the bottom!) they were practically opaque. It just took that long for the lenses to lighten. Coming out was marginally better, since the lenses darkened faster, but it still wasn't a good for the first hundred yards or so.

How about the old fashioned way? Squint going into a dark zone and open wide as you hit the shadows. When you hit the sunshine, squint again and gradually open your eyes. It's almost like your body was designed for such shenanigans!

Mandatory part of the YUPPY uniform...