Optical Illusion of The Day: Evening Dusk Optical Illusion

Posted: 11 Mar 2012 07:34 AM PDT

Illusions done by Akiyoshi Kitaoka, a Japanese professor of psychology have always been worthy of our attention. So what has he been up to lately? Let’s see if his “Evening Dusk” optical illusion brings something new to the table! Below shapes and figures give an illusion where it appears that the amount of light surrounding them is different compared to their insides. But there is another serious effect happening here – one messing with our brains and sight! Take a look at this figure below, before we proceed:

When light is bright, your eye constricts!

It probably gave you an impression that it’s much brighter in it’s center, compared to white background surrounding it’s outer edges. It also makes you believe that the amount of light inside it is much greater than it actually is, thus making your eyes constrict!

Why do our eyes constrict?

When light is bright, your eye constricts by contracting or dilating your pupils. It does this to protect itself from being damaged. What’s interesting is that scientists used to think this very fast reaction occurred completely as an automatic reflex, and that our higher brain wasn’t used.

If you compare the above figure with the below one, and if you measured the actual amount of light they both give off, you would quickly discover that the same amount of light is reaching your eyes. It’s just that your brain interprets the top image as brighter. But what’s really strange is that your eye alone thinks the top one is brighter, too.

The inside space surrounded by "petals" appears to be darker than the outer space!

Our eyes will actually constrict as a reflex when they’re looking at the first image, meaning that they constrict when the brighter light is only an illusion! This means our eyes and brain are reacting to what we think we see, rather than what’s really there! Researchers Bruno Laeng and Tor Endestad explain in their research that our brain and sensory organs react with each other much more than we realize. What they believe, is that we create illusions because they help us protect ourselves from possible future events.

See the below picture containing both shapes next to each other. Who would guess both of their insides were equal in brightness and amount of light they cast!