Eyeball reflections can reveal a 3D model of what you are looking at

Your eyes can reveal more than you might think, as researchers can now use computer vision technology to reconstruct 3D images of a scene from the reflections on a person's eyeballs. Jia-Bin Huang and his colleagues at the University of Maryland, College Park, developed a computer vision model that takes between five and 15 digital photographs from different angles of an individual's face while they look at a scene, and reconstructs that scene from the reflections in their eyes. The method adapts a technique called neural radiance fields (NeRF), which uses neural networks to determine the density and colour of objects the computer "sees". NeRF usually operates by directly looking at a scene, rather than viewing one reflected in a person's eyeballs. Huang's version builds the scene by extrapolating from a square of, on average, 20 by 20 pixels in each eye.