Smith Optics’s latest big window eyewear is this interchangeable Smith Optics Shift Mag. It ships with a clear lens that’s genuinely one of the best mountain bike glasses optics for dark and dank UK woods along with one choice of Chromapop lens more suitable to a variety of conditions from bright sunlight to mixed lighting. As we’ve experienced with many of the brand’s glasses and goggles over the years, these Smith lenses have superb clarity and contrast and minimal distortion.

Smith’s new optics system forges form, function and durability

The frame is flatter than many new generation glasses with a large window, which is really useful if you find that a more pronounced curve sees the lens touch your cheek bones. The malleable, two-position nosepiece pads also let you tune fit so that the glasses sit closer or further away from the face.

The whole Smith Optics Shift Mag system is extremely flexible and conforming, to the point I think that if you sat on the glasses accidentally, they’d probably spring back to shape, making them really resistant to damage or accidental knocks. Lens quality is superb in terms of optics and durability, and even if you need to clean them regularly after wet and muddy rides, it’s much harder to scratch and damage than on cheaper glasses. But therein lies the rub; there’s absolutely nothing to complain about in terms of performance or the rock-solid fit, but you definitely pay for that quality, as the near £200 price tag is quite salty and right at the very top end of the cycling eyewear market.