It's a matter of opinion, but we find riding eyewear to be right up there with gloves and helmets in the list of essential bike accessories. The range of things that could easily find their way into your eyes is extensive - dirt, grit, insects, branches - and you only get two eyes, so it makes a lot of sense to protect them. The problem is finding one pair of glasses to suit all situations. Weather and trail conditions are so variable that the usual solution is to have interchangeable lenses and switch between clear, middling and dark.

This is fine up to a point, but it doesn't allow for changing conditions during a ride. The classic example is following a trail across open, sunlit fields into dark woods and suddenly not being able to see anything. Or going the other way and being dazzled. We've taken to compromising by using an orange lens for pretty much everything, but it's still not ideal.

What would be ideal would be a lens that reacts to changes in light intensity, becoming darker in bright light and lighter as it gets darker. Photochromatic lenses have been around for years, but have had two major drawbacks. First, they're usually slow to react, taking several minutes to change from light to dark. Second, they rely on a coating on the lens that eventually wears off. And anything that "eventually" wears off under everyday circumstances will last about ten minutes in the dirt.

Specialized's new optics range changes all that, though. Its unique Adaptalite lenses make the photochromatic properties part of the lens material itself rather than being a coating, so it won't wear off and if you scratch a lens it won't hinder its ability to change tint. It's also fast-acting, taking a claimed 20 seconds from fully light to fully dark, while blocking 100% of UV A and B the whole time. The lens material is called NXT, and rather than the usual polycarbonate it's a polyurethane polymer. It's claimed to be unbreakable and 10-20% lighter than competing materials, as well as being optically superior.

The lens technology appears in a range of four glasses, two for road and two for mountain, using a slightly higher range of light transmission (25-65%) and designed to enhance contrast to help pick out trail features (the road glasses have a slightly darker range and are designed to cut glare). We've been using the Chicane glasses - the Singletrack is a similar style but smaller, so one or the other should fit your face. With only two styles to choose from, though, we'd expect that a fair number of people will find that neither is quite right.

The styling is distinctive without being too avant garde (although you'll probably want a pair of regular sunnies for off the bike), and there's a choice of frame colours. Fit is obviously rather subjective, but we found the Chicane to offer good coverage without excessively large gaps. In use, they're very good. Fogging is fairly minimal, and the Adaptalite lenses do work, making these glasses as happy in the woods as out in the open. You still get the temporary-blindness effect going from bright to dark trails or vice versa, but then even if the lenses reacted instantaneously it'd take your eyes a few seconds to adjust.

Innovative lens technology that does actually work, good shape, reasonably subtle styling

Distinctly high-end pricing, look a bit odd off the bike

Verdict This is Specialized's first foray into eyewear, and it's a great first effort. The Adaptalite lenses don't cover all the bases (night riders will probably want something clear) but they're happy in 90% of the conditions that most riders will encounter. If you're on a budget there are plenty of multi-lens options that perform well, but while high the price of the unique Specialized offering doesn't seem unreasonable.

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