The moment of clarity for cyclist Emily Brooke was less like an apple falling on her head and more like the prospect of a white van slamming into her.

Like many bicycle users before her, she realised that if the vehicle beside her on the road turned left, she would be squashed as she was in the driver's blind spot.

"I thought that if I was just 5 metres ahead, I would be safe – I wished I had a virtual me just 5 metres ahead, if I could just project myself there," the 28-year-old said.

About three years later, the designer has sold more than 3,000 Laserlight units from her company Blaze. Aimed at nighttime cyclists – 50% of urban bicycle commuting is during the evening or night – the aluminium device combines a light and a laser which projects a green image of a bike onto the ground 5 metres in front of the cyclist. It attempts to make drivers, who may not see the bike in their blind spot, aware of their presence, especially at night. It also alerts pedestrians about to cross the road.

Brooke got the idea while studying product design in her final year at the University of Brighton and looking at what the challenges were for urban cyclists.

"There is one statistic which stuck in my mind and that is that 79% of bikes that are hit are going straight ahead and a vehicle turns into them," she said. Another common collision, dubbed a Smidsy for "sorry mate I didn't see you", is when a driver comes out of a junction. Brooke wanted to tackle what she saw as being the biggest challenge for city cyclists. After dismissing other ideas, like creating a full hologram of herself, came upon the idea of projecting an image on to the ground to alert drivers.

Having left university, she created a prototype and was among the first tranche of companies to get the benefit of the wave of publicity that came with the advent of Kickstarter, gathering £25,000 in investment in five days and proving there was demand for the product.

"Naysayers are people who have not seen it. I completely agree with them, it sounds completely wacky. But when you see it in practice, it is a passive green bike, passively travelling on the road in front of you," she said. "It is the symbol of a bike clearly attached to a moving object moving along the ground in one direction, you see it and you orientate to 'where is the bike'. If it doesn't make sense when you first see it, you see it once [more] and then it makes sense."

Laserlights were shipped to preorders in January this year. Priced at £125, the light comes with a bracket to attach it to handlebars, is waterproof and the internally sealed battery is charged via a USB cable. The laser, assembled in Shenzhen in China, can only be used when attached to the bike. Both laser and light can be used at the same time, either flashing or in a constant beam. The green light is visible during the day but not effective, says Brooke, and is really aimed for night use when "you can't miss it". The bicycle symbol - instead of branding or writing - was chosen to ensure it was universally recognised.

Although her first use of the new device resulted in protests from a van driver, she claims reactions from drivers have been positive since and rejects suggestions that the device may be seen as a gimmick or unnecessary. "This started from a problem first. It started from six months of a problem before I even had an idea. I looked at tracking devices – a light that lights up the rider, that you have a head torch in your face – all sorts of concepts, but it was six months of understanding the problem before I came to the solution," she said. The relatively high price is as a result of the quality of the parts used, she says.

The company has just completed preorders and will now sell Laserlights through Evans Cycles shops in the UK as well as through its own website. Demand from the US – especially in cities such as San Francisco, New York, Seattle and Chicago – now accounts for half of sales, surpassing the UK. Purchases from renowned cycle-friendly cities such as Copenhagen and Amsterdam have highlighted different concerns for cyclists, said Brooke.

"For us it is personal safety and large vehicles. For them it is pedestrians stepping out in front of a bike and the Laserlight tackles that really well. Someone will see that symbol coming before they see me. It is enough for them to go 'Whoa, what is that' and hesitate on the pavement," she said.

The company has raised £500,000 in investment so far from, among others, Richard Branson's family and Index Ventures. Another round of investment, for £1m, is being finalised. Blaze now has six employees, including Brooke, and would be in profit but for investment in future products, she says, one of which will be a new type of rear light, expanding on her vision to become the company that caters for the urban cyclist.