If you or your child don't experience 3D movies they way other people do, you may have a binocular vision disorder that needs to be treated with vision therapy.
Here are some previous articles we have written on 3D vision and depth perception:
What is 3D Vision Syndrome?
Don't like 3D movies? You may have 3D Vision Syndrome
Take your kids to see "Thor": doctor's orders!
Life threatening disease found in girls eye - lack of 3D vision was the clue
Fixing My Gaze - Can you imagine not having 3D vision?
TED - ideas worth spreading - Susan Barry on how vision therapy gave her 3D vision