Geek Trivia

Saccadic Masking Is a Cognitive Phenomenon Wherein We Can’t See What Moving?

Objects During Eye Movement
Objects Aligned With The Sun
Objects With Very Low Contrast
Objects On The Horizon
Which Of These Caterpillars, Found Throughout The Southeastern U.S., Is Covered In Stinging Hairs?

Answer: Objects During Eye Movement

If we told you that you were blind for an estimated 30 to 45 minutes out of every day, you’d think we were either foolish or talking to the wrong person. Thanks to a curious visual phenomenon, however, every one of us is blind for a not insignificant amount of our day.

The amount of time in total might seem high, but that not-insignificant-amount is actually invisible to us precisely because it occurs in insignificant increments. Whenever we move our eyes from one object to another, our brain selectively blocks visual processing for a few hundredths of a second during the movement. We are, at that moment, effectively blind because the visual cortex is not processing the information. Don’t believe us? Go look in the mirror and alternate looking at each eye. No matter how hard you try, you can’t see the movement of your eyes because for the tiny fraction of a second they’re in motion and acquiring the new target, your eyesight is like a video recorder on pause waiting for the next show to start.

Image by Alexageev.