Blue light after dark squashes melatonin production Blue light exposure at night has been proven time and time again to be disastrous to your body's internal clockwork. Your brain tracks the time of day with special receptors in the eye that sense lighting conditions. These receptors are extremely sensitive to blue light. This is a problem because LED lighting and electronic screens blast blue-rich light directly into your eyes! These daytime signals after dark can scramble your natural circadian rhythm. Not Good… Block it!