A telescopic contact lens that can zoom in and out with the wink of an eye has been unveiled by researchers.The latest prototype, which offers hope to some of the 285 million people estimated to be visually impaired worldwide, was revealed at the American Association for the Advancement of Science annual meeting in California.
The 1.55mm thick lens contains an extremely thin, reflective telescope.
Small mirrors inside bounce light around, expanding the perceived size of objects and magnifying the view, similar to looking through low-magnification binoculars.
Optics specialist Eric Tremblay from the Ecole Polytechnique Federale de Lausanne in Switzerland also debuted complementary smart glasses that recognise winks – but ignore blinks – allowing the wearer of the contact lenses to switch between normal and magnified vision.
The user winks with their right eye for magnification and the left for normal vision.
First released in 2013 and refined since then, the hi-tech optical device magnifies objects 2.8 times.
Mr Tremblay said: “We think these lenses hold a lot of promise for low vision and age-related macular degeneration (AMD).”
The sight disorder is the leading cause of blindness among older people in the West.
Funded by the Defense Advanced Research Projects Agency (DARPA), the lenses were meant to serve as a form of bionic vision for soldiers.
Mr Tremblay stressed the device was still at the research stage, but was hopeful it could eventually become a “real option” for people with AMD.
He said: “It’s very important and hard to strike a balance between function and the social costs of wearing any kind of bulky visual device.
“There is a strong need for something more integrated, and a contact lens is an attractive direction.”
The telescopic contacts are currently made using a rigid “scleral” lens, unlike the soft contacts most people wear.
And while larger, Mr Tremblay said they were safe and comfortable.
The lenses are made from several precision-cut pieces of plastic, aluminium mirrors and polarising thin films, along with biologically safe glues.
Because the eye needs a steady supply of oxygen, the scientists have worked to make the device more breathable, using tiny air channels roughly 0.1mm wide within the lens.
The research team, which includes the University of California, San Diego, as well as experts at Paragon Vision Sciences, Innovega, Pacific Sciences and Engineering, and Rockwell Collins, said the device represented a “huge leap” forward.
There are glasses already on the market for people with AMD that have mounted telescopes, but tend to be bulky and difficult to use.
They also do not track eye movement, so the wearer has to tilt their head and position their eyes in a certain way to use them.