I couldn't see it either for 15-20 seconds. Must be a bug in human vision with this typeface. I wonder how many letters can be flipped while maintaining readability.
Aoccdrnig to rseearch, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.
I wish I could find the article I read debunking that. It really only works for short, common words. For an n-letter word, there are only (n-2)! permutations that fix the first and last letters. If your words average only 4.3 characters, you are nowhere near cmnioiaaortbl epsiloxon ttrrreioy.
A guy I know has a form of dyslexia (though I'm not sure this is the correct word) that makes him initially unaware (for a few seconds) of the difference between E and ∃ (and other vertically mirrored characters)
Imagine the horror of graph theory for him (e.g. ∃x,y E(x,y), etc.)
In the first alphabets, the letters didn't have a particular orientation. There was even this strange (to us) writing system of writing every other line as a mirror image. http://en.wikipedia.org/wiki/Boustrophedon
Wow, that actually seems more sensible than our style. It would save time scanning back to the beginning of the next line, and it would make it harder to end up on the wrong line, since different lines would be going different directions.