Polymers help glasses turn to sunglasses at the flick of a switch

New research into electrochromic polymer blends is helping scientists create eyeglasses that turn to sunglasses with the flick of a switch.

The technology is being designed to allow eyeglasses that can go quickly from clear to shaded and back again when the user wants them to, rather than passively in response to changes in light.

In a study led by Anna Österholm in John Reynolds' group at the Georgia Institute of Technology, the researchers point out that most transitional lenses now on the market don’t meet many users’ needs and are impaired by peripheral factors such as wearing a baseball cap or driving where the shift from light to dark is not quick enough.

In order to solve these issues, the researchers designed a new kind of lens that use of electrochromic polymers to create a wider variety of colours. The wearer can switch within seconds from clear to darkly shaded and back again in response to a small electrical charge that they control.

To make the lenses, the team says they used a method that could be easily scaled up for manufacturing.

The research, published in the American Chemical Society Applied Materials & Interfaces is receiving funding from BASF.