Hahaha! yeah, that happens to me too (thought it happened to everybody, apparently not!)

I have had a number of people complain about this. seems like it is really hard to track down. One possible causes is cataracts. The lens of your eye may not be transparent. It could have some color in it without significantly affecting the quality of your vision.

I have read that it is possible (although presumably extremely rare) to have a unilateral colour vision deficiency.You should try the Ishihara test for diagnosing colour vision - there are many available online, such as this one:http://www.toledo-bend.com/colorblind/Ishihara.aspSee if you get different results with your left eye, right eye, and both eyes together. Fascinating!Also, given that this is quite an unusual condition I suggest you might want to see an optician. I expect there is nothing wrong with you, just a rare genetic variation. However if I were you I would see an optician as soon as possible to rule out any serious eye diseases.

it's for your brain to be able to recognize two different images separated by a certain angle, so you can see in 3 dimensions

Woah, I noticed that too! I thought I was the only one. Heh.I always jokingly thought it was because life was a giant 3D movie and our eyeballs were like the 3D glasses.But I never really put much thought into it.