Product Review: Photocromatic Goggles
Skiing or boarding a slope with confidence requires good vision of the slope. As we might remember from school science lessons, the visible light spectrum, makes up the familiar colors of the rainbow: red, orange, yellow, green, blue, indigo, violet. Light colour is dependent on wavelength, and in overcast or snowy conditions, an overload of blue light bounces around to create what skiers call "flat light."
*Ski goggle lenses reduce the amount the overall light and often add one or more color tints to balance the spectrum for more contrast and definition to avoid flat light as much as possible. They are usually made for different conditions via the use of different lenses that differ by the varying amount of Visible light transmission (VLT or the percentage of light allowed to pass through a lens). A lens designed for sunny conditions does not let in much light, and has a low VLT percentage, (5 to 30 percent). A low-light or flat-light lens usually lets in much more light (from 50 to 70 percent). Traditionally this meant, the skier or boarder had to predict the weather for that day and select goggles or lenses accordingly.
But then some goggle manufacturers released photochromatic lenses which adjust its VLT to the conditions, meaning when the conditions change, so do your lenses. However, the effectiveness of photochromatic lenses is a subject of debate within the ski-goggle industry.
Some well known goggle manufacturers do not offer a photochromatic lens, because the chemical process that creates the change is temperature sensitive. They believe the cold weather common while skiing tends to make the lenses too dark. On the other hand, companies like Zeal Optics, swear by the versatility of photochromatic lenses. I tried out their Zeal Eclipse SPPX lenses recently whilst on a Heliski trip to Alaska and was generally pleased with the results. I noticed the lenses did change colour and I didn’t notice too much of a delay in doing so. As a bonus, they were also polarized.
Other eyewear companies like POC, Bolle, and UVEX also have also released photochromatic goggles, whilst others like Oakley have refrained, instead going down other routes like focussing on polarized lenses. I have also used, and love, Oakley’s polarized lenses but they are very expensive, a depressing thought as soon as you have a fall or worse sit on them and they crack.
Whatever lenses you are looking for this winter, I do recommend trying photocromatic, if you are looking for to simplify your life with just one set of goggles.
*Info sourced from Wikipedia and Ski Goggle Science Part 1: Light my way, by Eric Wagnon, The Examiner.