Colour-change lenses could help soldiers in urban combat

Lenses that change colour instantaneously to match ambient sunlight could help soldiers adapt more quickly in rapidly changing urban combat environments.

A team at the University of Connecticut led by Prof Greg Sotzing has perfected a method for creating quick-changing, variable colours in films and displays, such as sunglasses.

The typical material behind a transition lens is what’s called a photochromic film, or a sheet of polymers that change colour when light hits them. By contrast, the new technology uses electrochromic lenses that are controlled by an electric current passing through them when triggered by a stimulus, such as light.

The method uses a mixture of polymers in between the layers, creating the lens as it hardens. ‘They’re like double-pane windows with a gap between them,’ explained Sotzing.

The technology has captured the interest of the US military as a way to assist soldiers who need to be able to see clearly in rapidly changing environments.

For example, if a person emerges from a dark passageway and into the desert, a lens that would alter its colour instantly to complement the surroundings could mean life or death for some soldiers, Sotzing claimed.

‘Right now, soldiers have to physically change the lenses in their goggles,’ he said. ‘This will eliminate that need.’

Sotzing will begin a one-year sabbatical at the Air Force Academy in August, where he hopes to develop some of these ideas.

The mixture of polymers used in this lens also creates less waste and is less expensive to produce than previous mixtures, potentially making it attractive to the fashion industry, according to Sotzing, who added that sunglasses could be made with colours that move back and forth across the lenses.