R1RIDER posted this and I thought I would share it here as well:

Quick Eye Exam... This will blow your mind. Just do it - don't
cheat!!!!!!!!!!!! Try this; it's actually quite good. But don't cheat!



Count the number of F's in the following text:



FINISHED FILES ARE THE
RESULT OF YEARS OF SCIENTIFIC
STUDY COMBINED WITH THE
EXPERIENCE OF YEARS



Are you done counting?



Now scroll down only after you have counted them!



OK?



How many?



Three?



Wrong, there are six - no joke! Read again!

> FINISHED FILES ARE THE
> RESULT OF YEARS OF SCIENTIFIC
> STUDY COMBINED WITH THE
> EXPERIENCE OF YEARS
>
> The reasoning is...
>
> The brain cannot process the word "OF".
>
> Incredible or what?
>
> Anyone who counts all six F's on the first go is a genius...
>
> Three is normal.