Answer:
The cinema company make the 3D glasses big enough so that you can wear them over you're normal glassers! If they didn't do that, there would be SO MANY people complaining and moaning about how they couldn't see the film because they weren't allowed to wear their glassers!
From Aunt Sidney! x
well i have the same problem but i just pushed my normal glasses back and pearched my 3d ones on top it may be uncomfortable but i works for me :) sholaxxx