How do I look at a stereo figure of a protein to see it in 3-D?

My eyes can't seem to do it... and my temples hurt after trying.. what show i do?? any tips?How do I look at a stereo figure of a protein to see it in 3-D?
It's very difficult to explain as it tends to be one of those skills you either can or can't do.





I try focusing on a point past the back of the screen and then bring the focus point forward until the images overlap and I fully appreciate what you're saying about it giving you a headache.





Below is an example of a stereo figure.


http://www.nature.com/emboj/journal/v20/鈥?/a>