Our eyes converge inward as we look at an object moving towards us. In 3D it’s essentially the same thing: we converge (or “toe-in”) the angle of the left and right cameras, and this alters the particular 3D plane to which our focus is drawn. Objects in front of the convergence point appear to be coming out at us, while objects behind do the opposite. Care needs to be taken, however, particularly when fast cutting is used.

Read more: Why bad 3D, not 3D glasses, is what gives you a headache | PC Pro blog http://www.pcpro.co.uk/blogs/2010/08/02 ... z0w6NaybkL