Demetz x Marie Goncalves: trail sunglasses built for smaller faces

Less well known than Julbo or Oakley, Demetz has been all about optical expertise since 1950. The Lyon-based specialist has been developing its own models for outdoor sports for several years now. In our test, the G-SUIT stood out for three things: rock-solid hold, the quality of its photochromic lens, and a single-shield format that works especially well for slimmer faces.

A pair you forget you’re wearing

For this model, the brand leaned on an iconic reference from the G-SUIT line, but refined it further. The frame lines are sharper and the design feels more modern. Straight out of the box, the first thing you notice is how light they are, which matters with any piece of performance kit. On the run, they stay put despite constant movement. The adjustable temples wrap the head effectively, while the rubber inserts provide a reassuringly secure hold, including on technical downhills and rough terrain. Across our different outings, they didn’t creep forward, even with sweat or on more committed sections. Best of all, we didn’t get any pressure points after several hours, which is far from trivial on longer days out.

That comfort is reinforced by 3FIT technology, specific to the SUIT SERIES line. It lets you adjust the frame tilt across three settings: RISE for everyday use, RUSH for training, and RACE for racing and harder efforts.

A photochromic lens that really delivers

But it’s the optics that won us over most with this G-SUIT pro model. With a category 1 to 3 photochromic lens, the glasses react quickly to changing light, something you deal with constantly in trail running when you’re bouncing between forest, exposed ridgelines and shaded sections. The view is crisp, and details pop with real precision.

Transitions are smooth and natural, with no sense of visual discomfort. Contrast is excellent, making it easier to read the trail and anticipate what’s coming. Roots, rocks and uneven ground stay clearly defined even when the light shifts fast. That versatility also makes them a strong option for cycling. And the styling is understated enough to wear off the trails, too. Worth noting: the frame comes in several colors.

During our test, we didn’t see any fogging, whatever the conditions. The lenses are oleophobic, and even in hot weather ventilation did its job: sweat never got in the way of visual comfort.

Known for developing gear that can be fitted with prescription solutions, Demetz shows the breadth of its optical know-how here. The lens clarity is without question one of the model’s biggest strengths.

A smart balance for slimmer faces

In a market where many single-shield designs run oversized, the G-SUIT hits a rare sweet spot: not too wide, not too narrow. The lens still gives plenty of coverage to protect your eyes from wind, debris and sun, while keeping a sensible footprint. The result is a pair that suits smaller faces without feeling like the frame is taking over your whole face.

 The field of view remains impressively wide and panoramic thanks to the single-shield construction. Peripheral vision is clear, which keeps trail reading fluid even on technical sections. We really liked this blend of protection, understated design and comfort, something you don’t often see this well executed in this category.

A few areas to refine

The G-SUIT isn’t flawless, though. While the adjustable, grippy nose piece allows for precise fit, the pads could be more comfortable. After several hours, they can leave a few marks and become slightly noticeable.

Another thing to keep in mind: their position is fairly visible in your field of view. Some runners won’t notice it at all; others may find it distracting.

And like many photochromic lenses, the darkest tint doesn’t match a dedicated category 3 lens. In strong summer sun, we did experience some glare, as the lens never fully darkens.

Marie Goncalves at the heart of the project

That push for the right balance of lightness, stability and ergonomics owes a lot to Marie Goncalves, who was deeply involved in developing the model. Twice selected for the French national team and recent European team vice-champion at the European Off-Road Championships in Kamnik, Slovenia, the Lyon native will take on her first 100 km this summer at the CCC in August.

 I already liked Demetz models, especially the SUIT, for how light they are. But we realized one was missing. They looked a bit imposing, so we wanted to work on a version for smaller faces, which led us to create the G-SUIT pro model.

From the lens shape to the choice of colors, the athlete was part of the entire process. “For me, a good pair is a pair you forget you’re wearing. Photochromic lenses were essential because light changes are constant in trail running. I also use them on the bike, and even in grey weather, visibility is excellent.”

Staying close to athletes

Demetz’s aim to build a diverse collective appealed to trail runner and lawyer Marie Goncalves. “There’s a real human relationship and trust with the team, and the products are genuinely designed with athletes. I loved the idea of working with a brand that wanted to get into trail running, so it happened naturally.”

Founded in 1950 by Roger Demetz, an optician and passionate diver who wanted to solve the vision issues athletes were facing, the French brand was built around sports optics. After creating the first prescription diving mask, it now designs highly technical equipment tailored to the specific demands of each sport.

Based in Lyon, the company relies on a collective of athletes from very different backgrounds: Léonie Périault in triathlon, Jérémy Nicollin in cliff diving, Romain Attanasio in offshore racing and sailing, Steven Le Hyaric in ultra-cycling and adventure racing. And also Marie Goncalves, in trail running. A rare mix of sports, and just as many eyewear models designed to meet the real needs of each discipline out in the field.

Our take

With this G-SUIT pro model, Demetz offers more than just another SUIT variation. Built for trail running and developed with Marie Goncalves, it stands out for its excellent optics, clean design, dependable fit, and a size that finally makes sense for slimmer faces, something the market too often overlooks. Despite nose pads that could be improved and a lens that could go darker for maximum protection in harsh light, it’s still one of the standout successes in Demetz’s outdoor line.

Versatile thanks to its photochromic lens, it works just as well for trail outings as it does on the bike or even for road running. A pair that shows what the Lyon brand can do in performance sports optics.