Go stand in front of a mirror. Hold still, and look around, moving only your eyes. Look left, right, up, down. Look at one eye, then the other. Their reflection is right there in front of you, but no matter how hard you try, you’ll never see your eyes move. That’s because when your eyes are in motion, you briefly go blind — and you can’t even tell. This phenomenon is called “saccadic masking”.
Motion and human vision don’t mix so well. Objects in motion — like trains or the legs of racehorses — look like blurs. When you’re moving quickly, the world around you starts to blur, too. So theoretically, the world around you should blur every time your eyes move. Practically, however, this would be a mess. You’d be dizzy and motion sick all the time.
So the human brain has evolved to prevent constant blurring. The brain shuts off visual processing while the eyes are in motion and restarts it once they’re still again. In the “saccade,” the brief window of eye motion — which each last about 50 milliseconds — we can miss even major visual events, like a flash of light. And though less than a second of blindness doesn’t sound so serious, keep in mind that these tiny bursts of blindness happen thousands of times a day. Cumulatively, saccadic masking means we’re blind for about 40 minutes a day. (1)
We cannot see movement.
And yet, we believe in motion.
We see things which are dead.
And yet we believe in life.
We cannot really know anything.
And yet we believe we do.
Let go of your senses.
Trust not your eyes.
Do you feel alive?
Close your eyes.
And the whole world will start spinning…