Nothing ruins a good ski day faster than goggles that fog prescription eyewear like a hothouse in January. Most optically challenged skiers have already worked their way through a drawer of overhyped solutions to poor mountain vision. Prescriptions, dry winter weather and high altitude all point to one vexing conclusion: There is no across-the-board fix to seeing well on snow.
Large-frame OTG (over the glass) goggles are the most common option-and most prescription wearers know the frustrations. With larger chamber volumes and lens surface areas, OTGs can be slower to fog than standard goggles. But for the same reasons, when they do fog, OTGs generally take longer to clear. To make matters worse, OTG fog-outs are doubly problematic, blurring both the goggles and the glasses.
Another shortfall of some OTGs is optical distortion. Looking through a second lens compromises vision, and prescription value gets degraded as the curvature of a goggle lens increases, especially for peripheral vision. As your eye rotates away from the "sweet spot" directly in front of your pupils, oblique lens angles increase peripheral distortion. This can wreak havoc during a fast run and cause tired eyes and headaches.
There is no universal OTG remedy, and because goggle makers approach OTG design differently, you'll get many opinions on the best prescription solutions. But there are some basics to keep in mind.
Double-lens goggles and anti-fog solutions on interior lens surfaces help quash fog, while smaller-framed glasses reduce the interior surface area that snags moisture. Also look for a well-vented goggle, and make sure no part of your eyewear frames touches the goggle lens.
[250AD]Most OTGs encase your everyday eyewear, although companies such as Smith and Bollé offer prescription frames that attach inside the goggle. Just remember that the system isn't perfect, and there probably will be some peripheral distortion because of the dissimilar angles of the prescription lens and goggle lens. If distortion gives you headaches-and you don't mind sacrificing style for better sight-check out makers such as SeaVision, which imbeds a prescription lens in the goggle itself.
Prescription sunglasses are the other eyewear option. In mild weather, and with a close-fitting wrap frame, they're convenient, comfortable and good on-slope performers. But they're not without quirks.
While protective wraps sound like the obvious sunglass solution for prescription wearers, complications creep up with radically curved prescription lenses: distortion, depth-perception problems and a tendency to pop out because the frames can't secure the thicker lens edges.
Frame curvature is critical. Opticians measure curvature in "base" units. The human eye, for example, carries a 6-base curve; wrapped eyewear frames begin at a more extreme 8-base curve. As lens curvature increases, so does the difficulty in maintaining the prescription value. Pupil distance-the measurement from pupil to lens surface-is more exaggerated with wrap lenses, and prescription lenses need to maintain precise, graduated thicknesses as that distance changes. Producing these lenses is complicated and expensive, and only about 10 percent of the nation's optical labs are trained to do so. Extreme "coke bottle" lenses in the plus-or-minus 4.5-diopter range are difficult, and sometimes impossible, to fit into 8-base frames. One solution is high-index lens materials that offer thinner prescription lenses. The trade-off is a decline in optical quality. If you have wrap eyewear that your optician won't touch, there are several labs that can help. Two with good track records in the ski industry are Armex Optical (800-464-2763) and Opticus (800-870-5557).
Your best bet for prescription sunglasses lies with reputable optics makers that are in the sports-frame business. Some, such as Bollé and Panoptx, have in-house opticians who will fit wrap-style frames in most mild prescriptions; others require bbuyers to work with their own opticians to get prescription lenses.
Ultimately, the best solution is a matter of personal preference. To help you narrow down the choices, SKI suggests these five options. Click on the link to the right to check out SKI's suggestions.