Koo Open Sunglasses

Kask, the helmet sponsor of Team Sky, has launched an eyewear label called Koo, and these Open Sunglasses are the first to be launched under this new brand name. They feature novel rotating arms, large interchangeable lenses and, naturally, they work harmoniously with Kask helmets.

You'd think it would be obvious for a helmet manufacturer to also turn out its own eyewear, but surprisingly few of the leading helmet brands make their own glasses. Giro did for a brief period, while the most recognisable eyewear brand, Oakley, has never dabbled in the helmet market.

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The sunglasses are made in Italy and the frames have a unique rotating arm design. There's a small hinge at the elbow – flick it up and the arm can rotate away for storage. An added benefit is that it lets you rotate the angle of the lenses away from the face slightly – useful as a means of reducing fogging on longer climbs, though I still found it easier to simply pull the glasses forward on the nose.

The arms are lined with a rubber material to help grip the temples, and the rubber nosepieces can be adjusted easily to fit different nose sizes. There's a smaller nosepiece included in the box so you can really dial the fit, which I found to be really good, although they're a little less secure feeling on the head compared with Oakley's Jawbreaker. That said, they never actually slipped out of position during even the sweatiest riding.

Kask/Koo isn't messing around with the lens quality and has gone to the most recognisable name in the market, Zeiss. As you'd expect, the quality is superb with excellent clarity and they compare extremely well with other high-end cycling glasses. You get two lenses in the box, helping to justify the high price. The tinted lens is just right for everything from overcast to bright, sunny days, with the clear lens ideal for evening rides and night rides.

Changing lenses is pretty easy – simply rotate the small retaining tabs and pop the lenses out – but it's impossible to carry out the change without getting grubby fingerprints all over the lenses, unlike with Oakley's Jawbreaker design. You'll need to give them a clean using the supplied cleaning wipe or the soft bag they come with.

The lens is wide and tall and provides really good coverage as well as minimising frame intrusion to your vision, especially when in the drops or tucking your head down low. They're not quite in the same ballpark as the Jawbreakers, with a little more frame intrusion noticeable, but it's a lot less than many regular eyewear designs. For regular upright cycling, they are just fine and vision is unobstructed.

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Of course, the glasses have been designed to play well with Kask helmets, as you'd expect. I tested them with a Protone helmet and the fit was flawless, with no conflict with the retention strap. I also tried them with other helmet brands, including Giro and Lazer, and encountered no problems there either.

Kask is aiming high with these Open glasses, both in terms of performance and price. Judged on the former they live up to the high expectations and deliver a comfortable fit, easy lens change, good clarity and generous lens coverage. They are compatible with most helmet brands so you don't need to own a Kask helmet to be interested in them. They're available in a wide range of colours, and you get two lenses and a large protective case all helping to justify the high price. It's not the highest we've ever seen, either – you can certainly pay a lot more – but on the flip-side, you can pay a lot less.

Verdict

High-quality cycling glasses with easy interchangeable lenses