As has been stated, the problem is that the eye is focused on a 2D surface, but the brain has to interpret stereoscopic data. In real life you can normally loo

As has been stated, the problem is that the eye is focused on a 2D surface, but the brain has to interpret stereoscopic data. In real life you can normally look round a scene, focusing on objects of different distances as desired. But with a 3D film you can’t. You can’t look at an object which seems to be nearby and have it come into focus, as the camera may be focused elsewhere. And by trying to focus on something which isn’t there, everything else goes out of focus as well, confusing the brain and causing the migraines and nausea some people have. Also the 3D glasses don’t fit over my normal glasses, leading to a really awkward experience. I don’t think 3D films will be truly successful until we have light field or holographic displays, where you can focus on anything at will. It will also mean developing a new visual language for this kind of film, where the viewer can decide where to look, rather than be guided by the filmmakers. It’ll be exciting, and these kind of films will hopefully look quite different to what we see now.