One day, if your smart contact lenses are running low on battery, you may be able to fix that just by getting upset about it. Lee Seok Woo, a scientist and associate professor at Nanyang Technological University’s School of Electrical and Electronic Engineering in Singapore, has developed a battery that can fit inside a contact lens and can be recharged by your tears.
The battery is only 0.2mm thick, so it can fit inside a 0.5mm contact lens. Rather than lithium-ion cells found in most batteries, this one gets its power from a glucose coating on the lens that reacts when submerged in a saline solution. So you could charge your lenses when you have to take them out and store them, or you could do it with a few tears since those contain glucose.
Unfortunately, we’re still a long way away from getting these lenses commercially. Right now, the battery isn’t strong enough to maintain a wireless connection or onboard storage, and it can only last a couple hours between charges.
