If you don’t see black when you close your eyes, but “visual snow,” here’s the simple reason: “It has nothing to do with your vision”

When you close your eyes, not everyone sees complete darkness. Some people notice a kind of “noise” or tiny moving dots, similar to the static on an old television screen. The phenomenon can feel unsettling, but it has an explanation, and science communicator Miguel Assal has addressed it in one of his recent videos.

According to Assal, this sensation is usually not related to a problem with the eyes. “It has nothing to do with your vision,” he explains, noting that the source lies in the brain itself, specifically in the visual cortex, the region responsible for processing what we see. Even when we close our eyes and there is no visual input, the brain does not switch off. It keeps working, and sometimes that activity shows up as this “noise,” or visual snow. In other words, it is an internal interpretation, not something happening in the outside world.

The brain never stops

Assal also mentions what is known as Visual Snow Syndrome (VSS), a different phenomenon in which people see this type of interference constantly, even with their eyes open. In those cases, the perception is persistent and can be part of a broader condition. The key is to distinguish between the two. If the “snow” only appears when your eyes are closed and disappears when you open them, it is most likely just normal brain activity, with no meaningful clinical implications.

Experts agree that these kinds of perceptions are usually not a cause for concern. The brain, far from “shutting down,” continues generating signals even in the absence of light. Understanding that process helps normalize an experience that, while not widely discussed, is more common than many people realize.

Disclaimer: This content is for informational purposes only and does not constitute medical advice. If you have concerns about your vision or are experiencing unusual visual symptoms, you should consult a qualified healthcare professional or eye specialist.