See.Sense ICON3: The Bike Light That Reacts to the Road

This article is sponsored by See.Sense.

The clocks have gone back, and for most of us that means the ride home is now in the dark until March.

That matters more than it sounds. The Department for Transport's latest pedal cycle factsheet shows that on weekdays, cyclists are most likely to be killed or seriously injured between 7 and 10am and between 4 and 7pm. In summer that evening peak is daylight. From now on it isn't. The Royal Society for the Prevention of Accidents has been blunt about it for years: "We know that the clock change kills people," its then chief executive Errol Taylor said in 2019, pointing to a marked rise in vulnerable road users killed and seriously injured once the evenings get dark.

So this is the time of year to think properly about lights. And one small company in Northern Ireland has been thinking about them differently for more than a decade.

A light that reacts

Most bike lights do one thing. You pick a mode, and the light does that until you change it or the battery dies.

See.Sense lights have an accelerometer and a light sensor inside, and the software uses them to work out what's happening around you. When you're slowing for a junction, going round a roundabout or moving through traffic, the light raises its brightness and flash rate to catch the attention of other road users at the moments you most need it. When car headlights come towards you, the built-in sensor picks them up and the light flashes brighter and faster. And when you brake, the rear light switches from flashing to a constant beam plus flash until you move off again, which works a bit like a car's brake light.

The ICON3 is the third generation of that idea, and it adds a Super Visibility Mode, where the light uses a different, random flash pattern each time it reacts, to make you more visible at moments of risk. There's also an Adaptive Light Sensing Mode for daytime riding, and a Get Me Home Mode that dims the light automatically when the battery is very low, so you get at least one more hour of riding out of it.

The ICON3 reacts to filtering in traffic, road junctions, car headlights and roundabouts. IMAGE CREDIT: See.Sense

What's in the set

The ICON3 Set is a front and rear light. The front is rated at 575 lumens and the rear at 350, from a chip-on-board panel plus two focused LEDs, and both give 270° of side visibility. That side visibility matters at junctions, where a driver pulling out of a side road sees you from the side rather than head-on.

The ICON3 Set: rear light (left) and front light (right). IMAGE CREDIT: See.Sense

• Brightness: 575 lumens front, 350 lumens rear
• Side visibility: 270°
• Run time: up to 15 hours on Reactive Flash, and road.cc measured around 40 hours in Eco
• Charging: USB-C, about three hours from flat
• Waterproofing: IP67
• Weight: around 50g per light
• Mount: quarter-turn "twist and lock"
• Made in: the UK
• Warranty: two years

Crash alerts and theft alerts

Two of the ICON3's features work through your phone rather than the light itself.

Crash alerts, theft alerts and ride stats all live in the See.Sense app. IMAGE CREDIT: See.Sense

Pair the lights with the See.Sense app and you can set an emergency contact. If the light detects a crash, the app sends that person a text with a Google Maps link to where you are. road.cc's reviewer found it worked on the road, though it did send a couple of false alerts on steep, rocky gravel descents, which is worth knowing if your commute includes a towpath.

The theft alert works the other way round. Arm it when you lock up, and if the bike is moved while the light is still fitted, your phone gets a notification. BikeRadar found it worked well. It runs over Bluetooth, though, so it's for the bike locked outside the café or the office rather than the one left at the station all day, and thick walls can get in the way. It's a warning, not a replacement for a proper lock.

The road data

The road data is the reason See.Sense have ended up working with city councils as much as with cyclists.

Because the sensors are already measuring every bump, swerve and sudden stop, the lights build up a picture of the roads you ride on: rough surfaces, near misses, collisions and how smoothly traffic flows. Riders can choose to share that data through the app, and See.Sense pass it to the people who plan the roads.

The ICON3 rear light on the bike. IMAGE CREDIT: See.Sense

It started in 2017, when Belfast City Council, BT, the University of Bristol and Queen's University Belfast fitted See.Sense sensors to 200 of the city's public hire bikes to record road surfaces and near-miss events. The Lord Mayor called it a "world-first pilot project". Two years later, Dublin City Council asked cyclists to join an EU smart-city project that tracked speed, road surface quality, collisions and near misses across around 800 riders in Dublin, Antwerp and Manchester.

In London, the borough of Newham gave lights to 200 residents in 2023 to measure the effect of the new Romford Road active travel scheme. "Our data can identify issues and evaluate the scheme's impact in a data-led manner," Philip said at the time. See.Sense say they've also worked with Transport for London on its Vision Zero programme, using data from more than 1,000 riders to find where cyclists are swerving and braking hard.

Councils rarely have good evidence of where people actually ride or where they nearly get hit, because near misses don't show up in police collision records. A light that logs the rough surfaces and the close calls as you ride is a practical way to fill that gap.

Who's behind it

See.Sense was started by Philip and Irene McAleese, a husband and wife from Newtownards in County Down. Philip is an electronic and software engineer who studied at Queen's University Belfast and worked in industry for more than 20 years, and Irene has a degree in behavioural science and worked as a management consultant. They came back from Singapore in 2012, where Philip had been commuting by bike, and set up the company the following spring.

Their first light launched on Kickstarter in 2013 and raised £33,826 against a £12,000 target. The ICON followed in 2015 and raised £80,231 from 934 backers, and then in December 2021 the ICON3 went to Indiegogo, where it was fully funded within four hours. Its backers chose several of the ICON3's features, including the new mount, USB-C charging and the two new flash modes.

See.Sense have now sold more than 120,000 lights worldwide. They're still made in Northern Ireland, about 15 miles from the office, and See.Sense are the official bike light supplier to British Cycling and Cycling Ireland. In 2023 the ICON3 was a finalist for product design at the Irish Design Institute Awards.

What the reviewers said

road.cc gave the ICON3 eight out of ten, calling it "one of the cleverest lights on the market", with the caveat that for some riders it might be "just a bit too clever". BikeRadar gave the rear light four stars and described it as "something of a rear light on steroids". And Cycling UK's Cycle magazine called the 15-hour run time "genuinely impressive".

The criticisms are fair and worth knowing. Price came up in all three reviews, and road.cc found the charging indicator confusing. BikeRadar noted that because the light is always reacting, it can be hard to predict how much battery a ride will use. If you want a light you set once and forget, a simpler one will do. The ICON3 is for people who ride in towns and cities in the dark and want a light that's working harder at junctions than on an empty road.

A reader offer

See.Sense have given Velorution readers £60 off the ICON3 Set. Use the button below and the £60 comes off at checkout, or enter VELORUTION. It's £139.99 instead of £199.99, until Sunday 22 November 2026.

Get the ICON3 Set for £139.99 →

If you're putting together a winter commuting setup, my guide to 20 hi-vis things for cycling that don't look ghastly covers the clothing side, including See.Sense's reflective beanie.

And if you've ridden with See.Sense lights, I'd like to hear how you got on. Leave a comment below.

See.Sense sponsored this article and approved it before publication. Specifications are See.Sense's own, apart from the Eco run time and charge time, which come from road.cc's review.