rationalskepticism.org

According to Wikipedia http://en.wikipedia.org/wiki/RealD_Cinema RealD 3D screens use circularly polarised light ( and hence lenses) to achieve the effect. And rather than dealing with the plane of polarisation the lenses work by dealing with the handness of polarisation. Interestingly the RealD 3D web site did not in the quick look I had at it give the method of polarisation. (The lenses are available to prescription from all good optometrists - shameless plug )

I am so used to dealing with plane polarisation (cutting down glare from water surfaces etc) that at the moment I can't quite get my head around circular polarisation.