Why Do You See Stars When You Rub Your Eyes?

    If you have ever rubbed your eyes and started seeing stars, you might have wondered about the underlying cause. This reaction is normal and is known as phosphene phenomenon or photopsia. Phosphenes commonly occur as the result of external stimuli, such as rubbing your eyes, but the phenomenon can also occur spontaneously and some people have even reported seeing phosphenes while trying to fall asleep. People typically describe the experience of phosphene phenomenon as seeing stars, but in actuality, you can also see a variety of colors and geometric shapes.

    During the 1950s, German researcher Max Knoll developed a classification system for identifying phosphenes. Studying at the Technische Universitat in Munich, Germany, Knoll examined phosphenes in over a thousand individuals to create a classification of 15 categories which included stars, triangles, spots, spirals and even blobs. Knoll also determined that stimulating different areas of the visual cortex resulted in consistent creation of certain types of phosphene shapes.


    Researchers believe that phosphene phenomenon is caused by light that is emitted from biophotons, located inside your eyes . Since your atoms are continually emitting and absorbing particles of light, biophotons become absorbed into the body. Your eyes are not able to differentiate between regular photons and biophotons during the exchange, so both are sent to the optic nerve to transmit light signals to the brain to determine which are phosphenes.

    Although you may see quite a few phosphenes in your eyes when you rub them, there are actually far more biophotons created than what is visually recognizable. When your eyes are rubbed, it generates the biophotons throughout your eye, but most of them are absorbed. The phosphenes that you see are the result of some of the biophotons being absorbed by atoms present in your retina.

    Millions of rods and cones are responsible for collecting the light particles once they have been absorbed into the retina. Light particles are converted into electric signals which are sent to the visual cortex through the optic nerve. The brain combines these electric signals to reconstruct the image that your eyes had originally seen. However, if the reconstructed image isn’t decipherable, the brain won’t recognize it as a real depiction of anything and will categorize it as a phosphene instead.

    This is not to say that all experiences of the phosphene phenomenon are the result of the process occurring in the retinas. Some research suggests that phosphenes can also be created through electric and magnetic stimulation. Success in generating them through direct stimulation has prompted researchers to begin studying whether it is possible to trigger phosphenes in the blind, which may eventually enable them to see.

    Additional Contexts

    Seeing stars most frequently happens when you rub your eyes due to non-spontaneous phosphenes that are generated through pressure. This pressure causes excess biophotons to be released. As a result, it’s possible to experience the phosphene phenomenon whenever pressure is applied to the eyes. Other examples of situations that may cause you to see stars include sneezing too hard, standing up too quickly or experiencing head trauma.

    If you’ve been seeing stars lately before falling asleep or even when you rub your eyes, there’s no need to worry. The presence of these stars, or the phosphene phenomenon, only further demonstrates that your visual cortex is functioning correctly and that light particles are being transmitted to your brain effectively. However, if you begin to see phosphenes consistently while your eyes are open or notice that it is significantly changing how you visually perceive colors, you may want to consider having your eyes examined.

    Posted September 13, 2016 by Silverstein Eye Centers
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