You when you close your eyes and...see?

Close your eyes. What do you see? Not images, but color. I mean, color? Your eyes are closed!
How? Why? Is actually seeing or our imagination?

As you may already know,  basic color receptors, cones, are light sensitive cells. Behind the retina screen at the back of your eye, there are roughly 130 million of these cones. 

That's quite a few! Different cones respond the different wave lengths of light and send messages, if you will, along nerves to the brain and it's center of vision.


Recent (well recent enough) research shows that colors are received, or indeed recognized, in pairs. Most of the time, cones tend to pair red with green and yellow with blue. So, color pairing could very possibly be the reasoning for the color behind your closed eyelid. For example, afterimage optical illusions display this color paring.


Take a look at the following picture. Stare at the woman's nose. Look at the red dot only. Hols your stare for 30 seconds. Then, look at a blank surface, i.e. a wall, the ceiling...etc. Blink quickly a number of times and blink fast. Who do you see?

Amazing! The human brain is complex and genius. 

So there you have it. Cones and color pairing. Your eyes see a color and retain it for a short period of time. Hence why you just blinked at a blank surface and were surprised with a lovely picture of Beyonce! The blue and green dots are on her nose also to be paired and to create a colored picture when you blink.