Phosphene

Phosphenes happen when we see flashes or spots of light even though there are no lights in front of us. It can happen when we sneeze, rub our eyes very hard, or close our eyes tightly. We don't actually see anything or any light, but the brain makes us feel like we see a flash or a spot of light. This happens because of the special cells in our eyes called photoreceptor cells. The brain gets confused and thinks that the cells are sending signals even if there isn't any light around. It's like seeing stars in the daytime when you hit your head. The stars aren't really there, but your brain makes you feel like you see them. Similarly, phosphenes are not actually produced by light, but rather by the activity of the brain and the photoreceptor cells in the eyes.