Phosphenes are the visual sensations of light that occur without light actually entering the eye. They can be experienced when pressure is applied to the eyelids, during rapid eye movements, or even in complete darkness. This phenomenon is caused by the stimulation of the retina or the visual cortex in the brain. These light sensations can appear as spots, flashes, or patterns and vary in color and intensity. Phosphenes are often associated with activities like yoga, meditation, or visualization techniques, where individuals may intentionally induce them for relaxation or creative inspiration.