This little cone of plastic that fits on your eyeball is actually an extremely thin telescope that can be turned on and off with a simple wink of the eye.
The contact lens, developed by researchers at Switzerland's École Polytechnique Fédérale de Lausanne (EPFL) and funded by DARPA, is a scleral lens, a type of hard plastic lens usually used in niche medical applications. But here, the scleral lens is also embedded with thin aluminium mirrors -- essentially hiding a telescope on your eyeball.
Here's where it gets a little clunky though. The contact lenses have to work together with a special pair of liquid crystal glasses connected to an electronic system. The glasses can switch between polarising light at different angles, so it enters the eye -- and the contact lens-cum-telescope -- differently. Wink your right eye, and the light enters at an angle that goes through the contact lens's magnifying region. Wink your left eye, and light enters the normal region. Blink normally and nothing happens.
For now, the lens can only be worn for half an hour at a time because the rigid lens isn't permeable enough to oxygen. The researchers have already experimented with cutting tiny 0.1mm channels through the lens to allow oxygen flow, but allowing the eyeball to breath will be the major challenge ahead.
According to the makers of the contact lens, the most immediate applications for a contact lens that magnifies on demand could be for people who suffer from vision loss due to age-related macular degeneration. For the rest of us, though, we're just waiting for something to rival bionic eyes.
Pictures: Eric Tremblay and Joe Ford, via EPFL