Blue light after dark squashes your natural melatonin production Block it! Blue light exposure at night has been proven time and time again to be disastrous to your body'ÂÂÂ’s internal clockwork. Your body tracks the time of day with special receptors in the eye that sense light levels. They are extremely sensitive to blue light. This is a problem because any blue light exposure after dark creates conflicting signals. Your biorhythms can become fragmented and distorted. Not Good.