Technical Information and Definitions
Lens Colours
The lens colour used in sunglasses and goggles varies by style, fashion and use. For skiing and snow boarding purposes you must also consider the prevailing weather conditions to ensure optimum performance. The correct lens colour helps to improve improve contrast, eases eyestrain and generally improves your vision.
Grey lenses are considered neutral because they do not enhance contrast or distort colours. Brown and green lenses cause some minimal colour distortion but have contrast-enhancing properties particularly in diffused light. These colours perform best in bright sunny conditions, grey lenses are NOT recommended for skiing in snowy conditions but are excellent in bright sunshine.
Amber, orange, rose, pink and vermillion lenses are very popular amongst skiers. Best for medium and lower light conditions because they give good contrast enhancement. They help you to make out shapes, objects, and bumps in the snow more clearly because they block the blue (hazy) end of the colour spectrum but they do cause colour distortion.
Yellow lenses are commonly used by skiers for their excellent contrast enhancement and depth perception properties. They are especially effective in flat light or overcast conditions helping to increase visibility.
Clear lenses are used typically to protect the eyes from impact, debris and snow when skiing or riding at night or in very dull conditions.
Mirrored Lenses
Mirrored lenses reduce the amount of light that reaches the eyes and are therefore great at high altitudes and especially around snow and ice. The highly reflective coating greatly reduces the amount of light that reaches your eyes making them useful in bright conditions. Mirror coated lenses absorb anywhere from 10% to 60% more light than uncoated lenses. The colour of the mirrored surface is irrelevant to the colour of the lens. For example, a grey lens can have a blue mirror coating and a brown lens can have a silver coating. Mirrors do not get hot in direct sunlight and thus prevent scattering in the lens bulk.
Lens Materials
General sunglass lenses can be made from either glass or plastic. Plastic lenses are typically made from acrylic, polycarbonate or CR-39. Glass lenses have the best optical clarity and scratch resistance but can shatter or break on impact and so are not suitable for winter sports. Plastic lenses offer more resistance to shattering than glass. Of these polycarbonate lenses are the lightest and the most impact resistant making them the best option for skiing and snow boarding. The polycarbonate used to make lenses is safer than other materials because it is not brittle and holds up better under impact. It tends to absorb the impact rather than shattering although this is not a guarantee of non-breakage. Polycarbonate also has natural UV blocking characteristics and so does not need additional coatings.
Optically Decentred Lenses
Optically-correct decentred lenses provide superior optical clarity. They achieve this by undergoing a process where the thickness of a deeper base curve lens is horizontally tapered from the bridge area and becomes thinner at the outer edge of the lens near the hinge. This process eliminates prismatic distortion by shifting the optical sweet spot of each lens from the mid-point of the lens to directly in front of the eye. This is especially important with wraparound style ski sunglasses because of the high base curvature of the lenses.
Contrast
Contrast is the difference in brightness between the light and dark areas in your view. A high contrast lens gives you great visual acuity between light and dark areas. Brown, amber, orange, pink and yellow lenses filter out blue light waves giving a sharper high contrast view. The more common grey lenses are considered neutral because they do not enhance contrast or distort colours, as these are intended for use in bright sunlight this is not a problem when used as appropriate. If everything is white, contrast is very important.
Flat Light
When light is "flat," the slope looks like a white, empty canvas, and it's impossible to read the snow surface clearly. Ruts, bumps, ice, rocks, thin patches and even the edges of the piste disappear. And if you're out in an open expanse, it's hard to determine the pitch of the slope as your depth perception shrinks to nil. Flat light is usually experienced in overcast weather conditions.
Grilamid TR90 Frames
In theory, TR90 is a rugged, resilient frame material that's specially formulated for flex, impact strength and dimensional stability. In practice, it's tough enough to withstand the most aggressive physical punishment your body is willing to endure. No other material has the flexibility, remarkable toughness, and exceptional resistance to sun lotions and UV exposure. These elements allow designers to combine the frame material's light weight, impact resistance, flexibility in variable temperature and overall comfort to create durable models that surpass all expectations.
