These tiny camera lenses can ‘see’ like an eagle

Ever wonder what it’s like to have an “eagle eye?” Surgeons and spies alike may soon find out, thanks to a new camera lens that works the same way eagle­—and human—eyes do, despite being no bigger than a grain of salt. With spy gadgets in mind, scientists started working on the microlens a few years ago, but this new version features improvements to the lens’s field of view and focusing ability. Their latest version—cast in plastic with a 3D printer—acts like an eagle eye, they report today in Science Advances . The camera uses four lenses instead of one, each set at different focal lengths and mounted on an image-reading microchip that compiles data from all four lenses into a single image. These microlenses work by mimicking something called foveated vision, which allows many predators to see a wide field of view at low resolution and focus on a single object at high resolution at the same time. Humans can do this because our fovea, a small pit at the back of our eye packed with color-sensing cells called cones, is the only place where light hits the cones directly, which amps up clarity. Eagles have really deep foveae with lots of cones, which is why “eagle eye” is used to describe great vision. But the chip still has some limitations: Its resolution is low, and the chip is too bulky for some kinds of surgery. It also takes several hours to 3D-print each individual lens. But once those limitations are smoothed out, lenses this small could be used to go inside our veins, perhaps, or spy on culprits as supersmall surveillance drones.