{"id":2317,"date":"2010-09-08T09:00:43","date_gmt":"2010-09-08T16:00:43","guid":{"rendered":"http:\/\/www.todayifoundout.com\/?p=2317"},"modified":"2013-05-08T10:18:19","modified_gmt":"2013-05-08T17:18:19","slug":"what-the-things-you-see-when-you-close-your-eyes-and-rub-them-are-called","status":"publish","type":"post","link":"http:\/\/www.todayifoundout.com\/index.php\/2010\/09\/what-the-things-you-see-when-you-close-your-eyes-and-rub-them-are-called\/","title":{"rendered":"What the Things You See When You Rub Your Eyes Are Called"},"content":{"rendered":"

\"phosphenes\"<\/a>Today I found out<\/a> what the things you see when you close your eyes and rub them hard are called, namely “phosphenes”.<\/p>\n

A phosphene is characterized by perceiving some form of light when there is little or no light actually entering the eye, making it an entopic phenomenon (meaning the source of the phenomenon is within the eye itself). \u00a0Phosphenes are most commonly introduced by simply closing your eyes and rubbing them or\u00a0squeezing\u00a0them shut, tightly; \u00a0generally the harder you rub or squeeze, the more phosphenes you’ll see. \u00a0This pressure stimulates the cells of the retina and, thus, makes your brain think you are seeing light. \u00a0Specifically, Gr\u00fcsser et al. demonstrated that pressure in the eye results in activation of retinal ganglion cells in a very similar way to how they activate as a response to light.<\/p>\n

There are also several other ways phosphenes can be generated. \u00a0These include through: electrical stimulation; intense magnetic fields; hallucinogenic drugs (phosphenes not to be confused with\u00a0hallucinations, which are generated in the brain, not the eye); a blow to the head or a particularly severe sneeze where extra pressure is created in the eye on the retina and possible stimulation of\u00a0the visual cortex; low blood pressure, which can be experienced if you stand up really fast after you’ve been relaxing; exposure to radiation; meditation or extended visual sensory deprivation; various side effects from medical drugs; and certain diseases of the retina and nerves.<\/p>\n

The word “phosphene” was coined by surgeon JBH Savigny deriving from the Greek “phos”, meaning “light”, and “phainein”, meaning “to show”.<\/p>\n

If you liked this article, you might also enjoy our new popular podcast, The BrainFood Show (iTunes<\/a>, Spotify<\/a>, Google Play Music<\/a>, Feed<\/a>), as well as:<\/p>\n