KOO Open sunglass review: Clear and stylish, but prone to fogging

by James Huang


Kask helmets recently dove into the hotly contested cycling eyewear market with a new sub-brand called KOO. The made-in-Italy Open was the first model released, featuring a full-frame format, Zeiss-certified interchangeable lenses, an easily adjustable fit, and a choice of twelve different colors that — naturally — perfectly coordinate with Kask’s palette. But with the sunglass market already saturated with top-notch options, does KOO have anything unique to offer that sets it apart? Yes and no, according to CyclingTips U.S. technical editor James Huang.


Twist my arms

As it turns out, KOO does actually offer a fresh perspective, as the arms of the Open don’t hinge inward as usual. Instead, they pivot vertically, offering the same compact form of other sunglasses for storage when folded, but three distinct lens tilt positions when worn to fine-tune the amount of air that’s allowed to pass over the lens — something the company calls the Active Airflow System.

The Open also has a novel release system for swapping tints. Whereas many other interchangeable-lens glasses have optics that snap directly into the frame, the Open adopts a bit of a hybrid approach. Flipping up two small tabs on either side of the frame unlocks the edges of the lenses; the center portion snaps directly into the frame as usual.

The arms have three preset positions that allow you to adjust how much air is coming in over the top of the frame. KOO calls it the “Active Airflow System,” but it doesn’t seem to work.

Rubber inserts at the arms and nosepiece help hold the Open in place, and the nosepiece can be clicked into two different positions to adjust the height of the glasses on your face.

KOO includes two lenses with each Open — one with a dark grey tint for bright sun, another with a nearly-clear tint for heavily overcast days — along with a semi-rigid case, an additional storage bag, and a microfiber cleaning cloth. Retail price is US$239 / AU$298 / £170 / €199.

Keeping KOOL

As has been the case with every other pair of cycling glasses I’ve worn with the Zeiss logo, optical quality on the KOO Open is superb with no noticeable distortion and an exceptionally clear view of the world ahead of you. Lateral field of view is outstanding, but the upper edge of the frame is visible any time your head is tilted downward, unlike designs such as the Oakley Radar EV and 100% Speedcraft with their raised central lens tabs.

The Open’s tightly curved, full-frame design also offers fantastic protection. It made for quite a snug fit — at least on my face — and I never had any issues with wind irritation even on high-speed descents topping 80km/h (50mph). On rainy days, the dual-sided hydrophobic coating helps keep the lenses clear of water, too.

KOO has baked some genuinely innovative ideas into the Open, but whether they provide any real benefit is debatable.

That said, I found that the close fit also made the Open prone to fogging at lower speeds, particularly when climbing in hot and humid weather, and no matter how I adjusted the three-position earpieces. KOO may have wanted to avoid using traditional vents for whatever reason, but as is, there simply isn’t enough airflow with the full-frame design to keep water from condensing on the lens when you’re moving slowly.

Ultimately, I found it much easier to just pull the glasses off of my face entirely in those conditions.

Overall, I ended my three-month test period generally satisfied with the KOO Open glasses, but not quite wowed by what they had to offer. Style-conscious riders who already have a Kask helmet and are enticed by the idea of having a perfectly color-matched set of glasses will probably find enough here to sway their decision, but for me, there are other options I prefer.

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