BOLD Flash Photochromic Sunglasses – MTB, Ski & Lifestyle Eyewear

BOLD Flash Photochromic Sunglasses – Light-Adaptive Performance Eyewear

Lightning fast transitions, zero lens swaps. The BOLD Flash sunglasses are designed to keep up with changing light conditions and changing terrain — all in a sleek, performance-first frame. With a modern semi-wrap shape and light-adaptive photochromic lenses, Flash adjusts automatically from clear to tinted as the sun comes out or the trail dips into shade.

Perfect for mountain biking, trail running, gravel grinding, and backcountry ski laps, the Flash offers flexible, all-day clarity without compromise.

Photochromic Lens Technology
These lenses adapt on the fly, darkening in bright light and clearing up in overcast or forested conditions. No fumbling with lenses or squinting through the shade.

UV Protection: Fully UV Protected

Color Options:

• Black

• Blue/Yellow

• White

What’s Included: Custom box, hard case, lens cloth, and microfiber pouch — everything you need for wherever you go next.

Browse the full BOLD sunglasses collection.

Read our guide: Best Photochromic Sunglasses for Mountain Biking to see how the Flash compares for trail riding.

Technical specifications

UV protection and certification

What UV400 actually means

UV400 means the lens blocks 100% of ultraviolet light up to 400 nanometres. That covers the whole UV range that reaches the ground, both UVA and UVB. Independent lab testing measured 0.00% transmission across it.

Why UVB matters. UVB is the shorter, higher energy wavelength. Your cornea absorbs almost all of it, which is why the damage shows up fast. A day on snow without protection can give you photokeratitis, which is sunburn of the cornea. It feels like grit in your eyes and usually arrives six to twelve hours after exposure, often in the middle of the night. Long term, UVB is associated with pterygium, a fleshy growth across the white of the eye that skiers and surfers get, and with skin cancer on the thin skin of the eyelids.

Why UVA matters. UVA is the longer wavelength and it does not stop at the cornea. It passes through to the lens inside your eye and on to the retina. You feel nothing at the time, which is the problem. The damage accumulates over decades and is linked to cataracts and to age related macular degeneration. UVA is also present all day, all year, and it passes through cloud, so overcast days are not safe days.

Why it matters more on snow and at altitude. Fresh snow reflects up to 80% of UV straight back at your face, so you take it from above and below. UV intensity also climbs roughly 10% for every 1,000 feet you gain. A bluebird day at 10,000 feet on snow is one of the harshest UV environments most people ever stand in.

One more thing worth knowing. A dark lens with no UV protection is worse for your eyes than no sunglasses at all. The tint makes your pupils open wider, so more UV gets in. That is why the lab number matters and the tint does not tell you anything on its own.

What these standards mean

ANSI Z80.3:2018. The United States standard for non prescription sunglasses. It checks UV blocking, that colours still look natural through the lens, and that you can correctly recognise red, amber and green traffic signals.

ISO 12312-1:2022. The international standard for sunglass filters. It sets the filter category, verifies UV performance, and confirms whether the lens is safe for road use.

AS/NZS 1067.1:2016. The Australian and New Zealand standard, widely regarded as among the strictest in the world for sun protection. It is the one that measures UV blocking all the way out to 400 nanometres, which is where the UV400 claim comes from.

FDA 21 CFR 801.410. The United States Food and Drug Administration requirement for impact resistant eyewear. Every lens is drop ball tested. Impact resistant does not mean unbreakable, but it means the lens is built to resist shattering rather than breaking into fragments near your eyes.