Zollner Illusion
![](http://www.coolopticalillusions.com/illusions/zollner.gif)
Ahhh, yes. The famous Zollner Illusion. Don't the black lines look like the aren't parallel? Of course, they are - it's because of the feathered lines that make us perceive it differently. This is one of the classic optical illusions, and has been around since the 1800's, when Zollner created it.
![wavy lines optical illusion](http://www.coolopticalillusions.com/optical_illusions_pictures_3/images/wavypicture2.jpg)