KOO Open Cube sunglasses review

KOO Open Cube sunglasses review

Italy and Germany have teamed up to make the premium KOO Open Cube

Words and Images - James Raison

Kask decided to enter the eyewear game recently with their unusual pivot-armed KOO Open. Their second generation is the Open Cube with a redesigned frame, some slender vents, and interchangeable nose piece. That all sound lovely but I was excited by one word in paricular: Zeiss. That's right, Italy and Germany have collaborated on the Open Cubes. 


  • Open frame
  • Single ventilated lens
  • Folding arm pivot
  • Adjustable folding nose piece
  • Interchangeable lenses
  • 3 position arm angle adjustment
  • 30g weight


The fit and adjustment options make the KOOs a mighty comfortable pair of glasses. I mostly ran them “flat” or without any angle and swapped out the nose bridge to bring the glasses closer to my face. 


Once dialled in, they’re one of the most comfortable glasses I’ve tested. There’s little pressure on your nose, they’re light, and the bladed arms are smoothed out so they don’t slice up your ears. They wrap around your face in a deep, rounded arc, not slammed up against it. Visibility is excellent as a result with the single-lens design giving view of the world with very little obstruction.

Once on, they're immobile. No movement, or adjustment required as you swing your head around on the bike. 


The lenses in the Open Cubes are fantastic.

The lens is made by the maestros at Zeiss. They pass them through stringent lab testing for UV protection, visual quality at all distances, sharpness, durability, and scratch-resistance. The left lens carries a tiny - difficult to photograph, trust me I tried - Zeiss logo indicating their certification.

The Zeiss optics are truly outstanding

The Zeiss optics are truly outstanding

On the road you’re treated to exceptional clarity and razor sharp vision. The “Smoke Mirror” lens mutes sunlight and dials down colour saturation. Tones are the most neutral in all the sunglasses I’ve tested, which makes the world clearer and less noisy. The KOOs aren’t polarised but they do cut out much of the glare when the sun’s at a low angle - even better than some polarised glasses I’ve used. Riding into the rising/setting sun isn’t dazzling or dangerous like other sunglasses with inferior optics.

They manage fog rather well. I’m yet to find a completely fog-free pair of sunnies but the KOOs set themselves apart. Give the slender vents a chance to move some air onto your face and they perform well. They get a bit misty when air stops moving, like when you stop at the top of a climb they will fog up but clear hastily once you're moving again. Adjusting the arm angle so the top of the glasses are further away from your face helps the glasses clear up even faster. 


Arms on the Open Cubes pivot and rotate inwards rather than folding like most glasses. It's an unusual system. I'm a "folder" and like to hook my sunnies over the neck of my jersey or base layer when I'm not wearing them. The KOOs can't do that. 

I talk more below about how well they slot into Kask's own helmets, but not everyone will have the option to chuck them into a compatible lid. There's not much that can be done with the Open Cubes if you have a helmet with weird vents or no vents at all. You can put them in a jersey pocket but I rarely have the spare room. Those futurustic folding arms could prove inconvenient for some.



My Open Cubes came with clear lenses and a changeable nose bridge. I don’t use clear lenses much normally but these were very nice when I did. They don’t refract or dazzle you when headlights are blasting straight at your face.

Swapping out lenses and nose bridges is a rough process though. You have to yank the lenses out of the frame in a way that makes me nervous for the longevity of the small cutouts on the lens that the frame holds on to. I’ve found the nose bridge is ever-so-slightly loose since changing it out for the first time as well. 


Being owned by KASK, the KOO Open Cubes fit their helmets perfectly. My consistent gripe with the Protone and Valegro is how the cradle sits low and close to your ears, forcing a lot of glasses to be slotted under or dropped over the top of the cradle. The short, bladed arms on the KOOs slide slightly under the cradle and hold closely to your head with no clashing or interference. Lovely.

The KOOs slot beautifully into the Valegro

The KOOs slot beautifully into the Valegro

Further, the KOO glasses slot into the Valegro’s vents and stay there for on-bike storage. I couldn’t shake them loose even when intentionally bucking my head around. They site nicely in the Protone too, just not quite as firmly. Too many helmets fail to hold glasses in their respective systems - looking at you POC - but KASK have nailed it with the Open Cube and Valegro interface.


Buyers of KOO's Open Cube can expect exceptional optics, comfort, broad adjustability, good ventilation and fog management, and perfect compatibility with Kask helmets. Their folding arms could prove inconvenient for some depending on your helmet and how much storage you have in your jersey.

Australian RRP is a hefty $299, placing them among the highest price bracket glasses. The Open Cube's optics match everything I've tested at a similar price, including market juggernaut Oakley. If you're willing to spend on premium eyewear then add the KOOs to your list. Just be sure to try them with your favourite helmet!

Disclosure statement: The KOO open cubes were sent by Kask Australia for review. It isn't a paid review and we don't make any money from the sale of Kask or KOO products.