I found my blind spot! … No, really!

Some (if not most) of you will probably already know in advance what this following trick is about, but for those who don’t, follow these instructions: in the little animation below, stare at the small cross-like dot to the left, then close your left eye, keeping your right eye open and fixed upon that dot. You may want to position your face at about 1½—2 feet from the screen. I’ll turn you all into magicians, just you watch: through my awesome powers, I will make the large sliding circle … vanish!

Okay, so it wasn’t my magic – that’s just due to the built-in blind spot human beings have in their eyes, called a scotoma. You don’t usually notice it because one eye automatically compensates for the little blind spot in the other.

Pretty neat, eh?

(Not to mention, of course, that this is also further evidence for evolution and, correlatively, another strike against “Intelligent” Design … ;-))

Technorati tags: scotoma · blind spots · eyes · vision