What Do We See When We Rub Our Eyes?

If you close your eyes and rub them hard, you'll probably see dots, spots, and flashes and dashes of colors. These images are called phosphenes. They are produced by pressure on your eyes. Your optic nerve translates that pressure into all sorts or bizarre patterns. That's why being socked in the eye or hit on the head will make you "see stars".

If you stare at a brightly lit sheet of white paper or at a clear, bright blue sky for a while, you might see luminous points or spots of light darting around in front of you, just out of reach. Sometimes these spots appear as very bright circles with darker centers. They often appear to have tails, like comets. While no one is absolutely certain what it is you are seeing, the general consensus is that you are watching your own blood cells moving through the capillaries in your retina.



Sometimes, if the light is right, you can actually see the blood vessels running through your retina. This might happen in a doctor's office while your eyes are being examined through a special lamp that shines a light on the back portion of the surface of the eye. The "tree branch" pattern you see corresponds to your retinal blood vessels.



Those Mysterious Floaters :



Sometimes we notice spots that seem to float across our field of vision, especially if we are looking at a bright background. These "floaters" are usually caused by bits of debris floating around in the vitreous, the jelly-like substance that fills most of the eye.



These floaters flit between the cornea and retina, so the light entering the eye hits the spots and creates shadows on the retina itself - like a rotten tomato flying between a spotlight and the singer on stage. As we get older, the vitreous becomes more liquid and less jelly-like, and the floaters become more prominent.

While phosphenes are really physically induced hallucinations, there are a number of other things you can see on the inside of your eyeballs that actually do exist - like the blood and blood vessels inside your eyes.