KOO Supernova Photochromic Glasses Review

Koo launches its ultra-light, frameless Supernova glasses with photochromic lenses. The comfort of this model is thus further improved, especially in the changing conditions of spring.

By Guillaume Judas – Photos: ©3Bikes.fr / DR

Koo is the eyewear brand of the famous Italian helmet manufacturer Kask. The range offers different models, which you can choose according to your aesthetic preferences and the shape and size of your face. Already tested in spring 2022, the Supernova are very light with their minimalist frameless construction that offers a very wide field of vision, and they are thus very comfortable as long as you have a wide enough face for them to fit securely. In the absence of a frame, the rigidity of the glasses is very low, and you have to rely on a single, rather flexible lens to ensure a sufficiently covering fit.

This type of construction also prohibits lens changes, which limits the versatility of the model. With tinted lenses designed to combat the brightness of a full spring or summer day, the Supernova can be uncomfortable to wear in other conditions. But fortunately, the Italian brand is launching its model equipped with photochromic lenses (which adapt to light), comfortable to use, whether in bad weather, in declining light in the early evening, or in wooded areas.

The photochromic Supernova weigh 24 g, but ultimately it’s rather the absence of a frame that offers an unparalleled feeling of lightness, on the one hand with a field of vision that is not disturbed by any edge, and on the other hand with a flexibility that seems to hug the contours of the face. The rather long temples are likely to conflict with the back of the helmet for those with small heads, and you also have to get used to not feeling “tight” by the glasses. But it must be recognized that in use, the Supernova do not move, even on chaotic Gravel courses.

Lenses that adapt to conditions

Why should you opt for these Supernova with a photochromic lens rather than those with a tinted or “mirror” lens? A photochromic lens adapts to changes in ambient light in a few seconds, darkening or lightening to reduce eye strain while improving visual comfort. For glasses with a classic lens, you have to choose between several light filtration categories: from 1 (almost transparent lens) to 3 (high light filtration) at Koo for example, which correspond to approximately 70% down to 10% light transmission. Koo photochromic lenses offer light filtration from 11 to 73%, which normally allows them to cope with almost all conditions, and this in a few seconds.

Concretely, in full sun, the lens darkens to offer eye protection comparable to glasses dedicated to summer conditions. In shaded passages, the lens lightens, but it can be seen that it still remains slightly tinted (comparable to a category 2 lens, i.e. intermediate). And in bad weather, a shower, or with declining light as in the early evening, the lens becomes slightly pinkish, almost transparent.

The Koo Supernova in the field

The Supernova are still surprisingly flexible and light, once on the face. You adapt quickly, even if you are used to wearing glasses that are a little more present, a little heavier and more rigid. Ultimately, where the flexibility of the Supernova is most annoying is when trying to place the glasses in the helmet’s ventilation holes, for example during a long climb with sweat running down the face. Because this flexibility limits good support, and it is possible to lose the glasses in these conditions.

In use, the change in lens filtration according to conditions is very fast, to such an extent that it is difficult to photograph if you try to hide only one part of the lens for demonstration. It should also be noted that a clear distinction must be made between actual brightness and perceived brightness. In good weather and in a shaded area, the lens still remains slightly dark because the light is indeed present, even if by contrast one may have the impression that there is a big difference with full sun.

In gray and humid weather, the glasses always offer good visual comfort. This is all the more appreciable as the lens benefits from a hydrophobic treatment that promotes water runoff. The absence of a frame and the cut of the lens on the upper right and left corners are sufficient to prevent any fogging while riding.

It is only in gray weather and when passing through wooded areas on Gravel courses (therefore sometimes very dark) that the limits of this type of product are reached. Even at its clearest, the lens is not totally transparent and still filters 27% of the ambient light. This requires adaptation and a slight effort to clearly see stones and other roots, more so than without glasses. But we have observed this with other glasses with photochromic lenses, and sometimes, a totally transparent lens or no glasses at all may be preferable for visual comfort.

The fact remains that the Koo Supernova with photochromic lenses are rather high-performing in almost all conditions, and only their rather high selling price of €210 can make one think twice.

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