Ekoi E-Lens Evo electronic glasses

These Ekoi E-Lens Evo glasses use an electronic lens to adapt to the surrounding light conditions, and they do that in the fastest time I've ever witnessed. If you aren't concentrating you won't even notice – it's not just a gimmick. It does make them very pricey, though, so you'll need to decide whether those fractions of a second are worth the outlay.

For more options, check out our guide to the best cycling sunglasses.

> Buy now: Ekoi E-Lens Evo White Revo bleu Revo red for £362.07 from Ekoi

Even without the electronic wizardry of the lens, the Ekoi is still a high-performance pair of sunglasses with a secure fit, helped by fully adjustable arms that you can tweak to wrap around the shape of your head, and a grippy nose bridge that stops them moving when things get sweaty.

There is no adjustment of the nose bridge, like you get on some glasses, but I didn't find an issue with that. I rarely have to tweak glasses to fit, but if you do, it's worth bearing in mind. You also get two sets of arms, one short pair, one long, to help achieve the right fit.

I found the E-Lens Evos very comfortable to wear, and most of the time I didn't even notice that I had them on once I'd been riding a bit.

It was only when I glanced over my shoulder and could see just a small section of frame that I was reminded of them. It's not enough to obscure your vision, though – my view was never hampered at all.

You also get great clarity from the lens. The lens is Revo Red on the outer side, with the inner being Revo Blue, and together they bring a slightly bluish hue to the outside world, but not enough to distort the colours overall.

Being polarised means the lens blocks reflected light, so you always get a crystal clear view in front of you.

The lens itself is created by Optrel and is called Shadetronic. It works by liquid crystals within the lens reacting to the changing electrical voltage generated by the lens's solar cells. The brighter the outside conditions, the darker the lens goes, and vice-versa.

Because the glasses are charged by the sun there is nothing to plug in and everything is waterproof, so no worries if you get caught out in the rain.

The response time to the shade change is the fastest I've ever known from any photochromic glasses I've worn. Ekoi says it happens 'in less than a 10th of a second', and you literally cannot notice these lighten or darken unless you really focus on them as you move from full sun to shade and back again.

The lens darkens more at the top which is a real bonus as it minimises glare from the sun high up in the sky without affecting brightness levels when you are looking down at the road. The light range goes from category 2 to category 3, from 20% to 80% ABS (the amount of light absorbed by the lens).

I found them fine to use on cloudy days right up to bright sun.

I've been testing these since early summer, and we had one of the highest levels of grass pollen I've known for a few years. But with no gaps in the lens and plenty of wraparound to keep airflow at bay, I didn't suffer with itchy eyes at all.

As for the build quality, there is nothing to complain about here – these are very well put together glasses.

The frame is made from Grilamid, which is a thermoplastic used by the majority of manufacturers, while the lens is made from polycarbonate.

The white frame option on test looks to be resistant to stain from sweat, road spray and rain, and there are some cool little details like the arms being held in place by small screws rather than just being clipped into the frame.

Value

The price fluctuates with the exchange rate, and is currently £362.07 (at one point it was £297.37) – this technology doesn't come cheap. These are some of the most expensive glasses we've reviewed, beaten only by the £543 Bollé Lightshifters that were fitted with prescription lenses, and the £699 Everysight Raptor 'smart' glasses, which had GPS and a camera built in.

Even the Engo Eyewear Engo 2s, which connect to your phone and come with a heads-up display, are cheaper at around £280.

If you're happy with a fractionally slower change then photochromic options can be had for a lot less, like the Rudy Project Deltabeats at around £130 that Anna tested last year, or the Magicshine Windbreakers that Suvi reviewed earlier this year, at just £49.99. They won't react as fast as the Ekois, but that's a big saving in cash.

Conclusion

For me personally, I'm not sure I could justify the cost over some photochromic glasses I've worn, but if you want a pair of sunnies that have the fastest reaction times, you will enjoy using the Ekois. They are expensive, but the performance is very impressive, as is the overall build quality, and they fit really well too.

Verdict

Quicker to change than standard photochromic glasses, but you pay extra for that speed