Light-Sensing Cells in Your Eyes Control Sleep: Beyond Vision
How Do Your Eyes Control Sleep and Circadian Rhythms Beyond Vision?
Through intrinsically photosensitive retinal ganglion cells (ipRGCs), specialized cells in your retina that detect light specifically for circadian regulation, not vision. This groundbreaking discovery revealed that your eyes contain a “third” light-sensing system, separate from rods and cones used for vision, that directly communicates with your brain’s circadian clock. These cells contain melanopsin, a unique light-sensitive protein that responds primarily to blue light and sends timing information to the suprachiasmatic nucleus to synchronize your biological rhythms with the day-night cycle.