TriEye exists because of a crash. In 2016, founder Carsten Juell Fongen was riding with his family on a dusty mountain road in Norway when his own son hit him from behind. Lying in the gravel, he had the idea that became the company: stop bolting mirrors onto bikes and build one into the lens instead. Two years later, after the patent came through, the first pair launched on Kickstarter.
Most product-origin stories are written backwards, polished until the founder looks prescient. Ours starts with a middle-aged man bleeding on a gravel road in the Norwegian mountains, wondering what just hit him.
It was his son.
What happened on that road in Norway?
In 2016, Carsten Juell Fongen was out riding with his family when he braked and his son — about a metre off his wheel — went straight into the back of him. Nobody saw it coming, least of all Carsten.
He is blunt about his share of it. He did not expect anyone to be sitting that close on a fast, dusty descent, and he grabbed the brakes without a thought for what was behind him. That is the honest version, and it matters, because the fix he went looking for was not "make other people ride better." It was "give me a way to know what is back there without turning around."
The idea arrived immediately, before he was even upright:
"Still lying bleeding in the road, I got the idea to integrate a mirror into my eyewear."
— Carsten Juell Fongen, founder of TriEye
Then the part every founder recognises: "Would it work? That was the key question."
Why is the shoulder check the dangerous part?
Turning to look behind you costs you balance and line — the bike tends to drift toward wherever your head goes. That is the whole problem in one sentence.
You already know the feeling. You twist, the bars follow a few degrees, and for about a second you are riding slightly off-line with your eyes pointed away from the road ahead. On an empty lane that is nothing. Closing on a wheel, or with a car coming through, it is the least useful second of your ride.
Researchers at KU Leuven and VU Amsterdam put numbers on how hard that manoeuvre actually is. They asked 40 younger riders (average age 23) and 41 older riders (average age 63) to cycle in a straight lane and glance back to identify the colour of an object behind them. One-third of the older group failed the task outright — misidentifying the colour, losing balance, or riding out of the lane — and even on successful attempts they showed greater steering variability and took longer than the younger riders. Their own recommended fixes include wider bike lanes and, explicitly, mirrors. Worth noting honestly: that paper is a preprint and has not yet been through peer review.
That is a study about older cyclists, not a claim about everyone. But it measures the thing Carsten felt on that road — that a shoulder check is a real balance-and-attention task, not a free look.
Why not just fit a normal bike mirror?
Because he tried, and the existing options each ask you to give something up. Bar-end and helmet mirrors work — they just come with trade-offs riders quietly stop tolerating.
A handlebar mirror is stable and cheap, but it sits low and wide, catches on things, and shows you a lot of your own hip. A helmet mirror gives you a good field of view and moves with your head, but it bobs on rough ground and needs re-aiming. Both are fine tools; we say so plainly in our comparison of bike mirror types.
The gap Carsten saw was different. Your eyes are already behind a lens. If the mirror lives in that lens, it travels with your line of sight, adds nothing to the bike, and the glance costs you no head movement at all. That is the entire design thesis, and it is why the mirror on a pair of TriEye glasses is built into the lens itself — never clamped to the temple or the arm. We break down the optics in how the integrated mirror works.
How did an idea in the gravel become a product?
Slowly, and as a family business. Development started in 2016; the first model reached customers in spring 2018, once the patent process was finished.
Carsten's three children took on product development, production, and sales and marketing as the thing grew. The company's first trade-show stand at Eurobike in Friedrichshafen was run out of two tents at the local campsite, because the travel budget did not stretch to hotel rooms. That trip ended with the Public's Choice award for start-ups.
| When | What happened |
|---|---|
| 2016 | The crash in the Norwegian mountains. Development of an in-lens mirror begins. |
| Spring 2018 | Patent process completed; the first model launches on Kickstarter. |
| 2018 | Eurobike debut in Germany — Public's Choice, best start-up. Taipei Cycle d&i award the same year. |
| 2019 | ISPO Award Gold Winner, Outdoor / Biking category. |
| 2020–21 | First professional investor comes on board; a new model is designed from scratch. |
| Late 2021 | The View launches — the third-generation design, and still the core of the range. |
| Today | Used by 40,000+ riders and rowers across road, gravel, commuting and sculling. |
What did we get wrong along the way?
Plenty. The first versions were function-first and looked it, and early riders told us so — a mirror you are embarrassed to wear is a mirror you leave at home.
The second thing we underestimated was how personal the setup is. We build the mirror into one side of a single shield lens, and the wearer's left is our default, because that is the traffic side in most right-hand-drive countries. But riders on the other side of the road, and rowers watching a specific bank, often want the opposite. So the range covers a mirror on the left side, the right side, or both sides of the lens — a dual setup, which ships with the larger mirror where a single ships with the smaller one.
The useful part: none of that is locked in when you buy. TriEye lenses swap out, so the mirror side, the mirror size and the tint can all change later — you can move from a single to a larger dual mirror without replacing the frame. That surprised us too; it started as a manufacturing convenience and turned into one of the things people like most. We cover it in are TriEye lenses interchangeable.
What the mirror does — and what it doesn't
A mirror helps you see what is behind you. It does not prevent crashes, and we will not tell you otherwise.
Here is the honest framing we hold ourselves to. Being hit squarely from behind is not the most common way cyclists crash — junction and side-on collisions dominate the statistics. What a mirror changes is not your odds; it is the fact that one direction around you is simply unknown until you turn your head.
And the group-riding angle is real. In the Taupo Bicycle Study, which followed 2,590 adult cyclists in New Zealand for a median of 4.6 years, researchers recorded 66 on-road crashes per 1,000 person-years — and riding in a bunch was among the factors that predicted a higher risk. Carsten was not taken down by a truck. He was taken down by a rider he could not see, on a ride with people he loves. That is the specific blind spot the product was built for, and it is why the story sits alongside pieces like whether you actually need a rear-view mirror for cycling and Dr. Jim Taylor's account of the crash that changed how he rides.
A mirror will not ride the bike for you. It just means the road behind you stops being a guess.
Frequently asked questions
Who founded TriEye, and what is the story behind it?
TriEye was founded by Carsten Juell Fongen in Norway. In 2016 he was hit from behind by his own son while riding with his family on a dusty mountain road, and had the idea for a mirror built into the lens while still lying in the gravel. The first model launched on Kickstarter in spring 2018 after the patent process completed.
Is TriEye a real company or just a Kickstarter project?
It is a Norwegian company that has been shipping since 2018. It won the Public's Choice start-up award at Eurobike 2018 and an ISPO Award Gold in the Outdoor/Biking category in 2019, took on its first professional investor in 2020–21, and now has more than 40,000 riders and rowers using its eyewear.
I ride in a club group and keep getting surprised by wheels behind me — would a cycling mirror actually help, or is it just for traffic?
Group riding is exactly the case TriEye was built for — the founder's crash involved another rider, not a car. A mirror lets you see who is on your wheel before you brake, move out, or take a turn, without the shoulder check that pulls your line sideways. It does not replace a proper lifesaver look before a real manoeuvre.
Which side does the mirror go on, and am I stuck with that choice after I buy?
The View has one shield lens with the mirror integrated into it, on the wearer's left side, the right side, or both sides for a dual setup. You are not stuck: TriEye lenses are interchangeable, so you can change the mirror side, move from the smaller single mirror to the larger dual, or swap the tint later using The View Spare Lens.
I already wear prescription glasses for riding — can I still get the rear-view mirror?
Yes. The Clip is a clip-on mirror that attaches to the glasses you already wear, so you keep your own prescription lenses. It is single-mirror only, and it is the usual route for riders who do not want a second pair of glasses.
Does a rear-view mirror stop you getting hit from behind?
No, and we will not claim it does. A mirror helps you see traffic and riders approaching from behind so you can react earlier; it does not change how other people ride or drive. Rear-end collisions are also a minority of cyclist crashes — junction and side-on impacts are more common. What the mirror removes is the blind direction, not the risk.
