Photochromic Lenses: How They Work on Water and Snow
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Light changes during a session. A kite session that starts under morning cloud ends in full sun. A ski day moves from bright ridges to flat light in the trees. A photochromic lens adjusts with it, so one pair covers the whole day.
How it works
The lens contains molecules that change shape when ultraviolet light reaches them. In their activated state they absorb visible light, and the lens darkens. When the UV drops, they fold back into their original shape and the lens clears. It happens continuously, in both directions, as the light changes.
On our photochromic sunglasses, the lens moves between category 1 in low light and category 3 in bright sun. That covers most conditions from dawn to midday.
How fast
Darkening is quick: most of the change happens within the first minute in strong sun. Clearing takes longer, usually a few minutes. Riding out from under a cloud, you'll notice the lens catching up rather than switching.
Temperature changes the result
Cold makes photochromic lenses darker and slower to clear. Heat makes them lighter. On snow, in the cold, they reach their darkest state and hold it. On a hot day on the water they may not get quite as dark as a fixed category 3 lens, which is worth knowing before you pick one for a tropical spot.
Behind glass
Car windshields block most UV, so photochromic lenses barely darken while you drive. For the drive to the spot, a fixed-tint pair works better.
When to choose photochromic
- You ride at dawn, at dusk or under changing cloud.
- You want one pair or one goggle instead of several lenses.
- You ski in mixed conditions, from sun on the upper slopes to flat light lower down.
If you ride mostly in hard midday sun in warm places, a fixed category 3 polarized lens will usually be darker and more consistent.
Photochromic in our range
On the water, Jeri, Essaouira, Boracay, Leucate, Race and Chameleon come in photochromic versions, as does the La Ventana goggle. On snow, see all photochromic ski goggles.