The depth sensor is used on smartphones for features like face unlock. This works by using thousands of laser points to map facial details, which require a fast processor and a large battery to do a lot of calculations. Researchers are looking for ways to perform similar functions but in small devices with limited battery life, such as smart watches or microrobots.
To find a more efficient way to measure depth, they turned to spiders for inspiration. Unlike humans, where each eye captures slightly different images and the two are compared to measure depth, jumping spiders require very accurate depth perception even though their brains are small. So they have a retinal layer in each eye that captures images with varying degrees of blur. An object will appear blurry in one eye and sharp in the other eye, which allows efficient depth calculation.