Why Do We Roll Our Eyes

Satoshi KashiiJapan Speaker Why do we roll our eyes? The fundamentals of vision—light perception, visual acuity, and the visual field—are perceived by the brain through complex logarithmic transformations of external stimuli. This mathematical operation is performed by the axonal projections of neurons from the retina through the optic nerve to the visual cortex (V1). The complex coordinate transformations are actually the result of intermolecular forces. However, vision is not simply a static perception of images on the retina. Through the oculomotor system, the brain dynamically and predictively captures objects, reconstructing the external world within the brain while reproducing visual images. Without moving the eyes, it is impossible to perceive depth. For example, fixating on the center of a slanted pencil, cover your right eye. You will immediately notice the upper end tilted temporally. Covering the left eye induces an outward (temporal) tilt of the upper end. The perceived images of a vertical object in each eye are extorted. Here, we roll our eyes to optimize the cyclodisparity stimulus for stereoscopic depth perception in the pitch plane—that is, to see things in 3D: length, width, and “depth”. But that’s not all. Vergence eye movements are not essential for stereoscopic depth perception. We do not need to roll our eyes to see things in 3D once we have learned and developed binocular vision during the critical period of visual system development. The key to 3D vision lies in neurodevelopment during infancy.