This is the reason why you see colours when you close your eyes

Ever noticed how when you close your eyes or rub them, there seems to be a spectacle of lights forming swirling patterns of colours inside your closed eyelids? Trying to rub sleep from your tired eyes somehow only intensifies the display, only to settle down again after a few seconds. There’s a reason (or a number of them) why this happens. Read on to find out.

Why does this happen?

The swirls and patterns you see are scientifically referred to as ‘phosphenes’. These can start in the eye or the brain, but what most people normally perceive is as a result of the normal functioning of the retina – the layer that lines the inside of the back of your eye, writes Katrina Schmid, Associate Professor, Queensland University of Technology in The Conversation.

These phosphenes are a normal part of how our eyes work. Our eyes don’t turn off in the dark, but instead they create very weak internal signals that mimic light. These signals are constantly being made by the cells at the back of your eyes.

The swirls and waves you see when you close your eyes are made by changes in activity from these cells. The blobs may be coloured because the cells in your eyes that detect colour also show this activity.

How normal is this?

Dr Schmid added that seeing colours when you close your eyes is totally normal. Some people notice them, and some do not. However, much more obvious phosphenes can occur in some eye diseases.

If what you’re seeing has changed, and the patterns of light become much more noticeable or hang around for longer, it could indicate a problem.

She advises seeing a specialist if you notice a change any changes in the swirls and colours you see when your eyes are closed.

Sources used:

The Conversation: Curious Kids: why do we see different colours when we close our eyes?

Scienceline: Why do we see colors with our eyes closed?

Huff Post: Why Do I See Patterns When I Close My Eyes?