How can I make these optical illusions? :P

[martin.dren]

Hey,
Happy New Year! Just wondering if you guys know how I can make these types of optical illusions:

http://www.stareclips.com

It's really flipping neat! :p Anyone know? :) It can't be inverted images cause I tried that with one of my own images and that didn't work lol.

Any help would be appreciated :)
martin.dren

[NEMESIS]

Hi,
I will provide you an idea for "do it by yourself" optical illusion. All you need is Photoshop (any version is ok :D) so let's begin.
First open blank document and on a new layer draw a gradient from black to white or visa versa. And again on a new layer draw rectangular selection from left end to right end of the document but height of that selection should be 1/5 of the height of overall document or max 1/4. And fill that selection with 50% grey. Try and see what effect this produces. Brain sometimes can be nasty for our eyes :D

See ya, i hope you will enjoy this