Bicycle Safety: How does Volvo's new invisible reflective paint work?

An invisible yet highly reflective spray paint debuted in the UK a few days ago, as part of a campaign by Volvo Car to increase cycle safety. Life Paint promises to be invisible on clothes and bikes, washable and non-permanent. But the glare of a headlight will cause particles in the paint to reflect light back to the driver, making the cyclist glow.How does this direction-dependent paint work and can it really make a cyclist safer? Credit: Screenshot from the Volvo Car Life Paint video campaig...