How do the new kind of 3D gles work?

When I went to a 3D movie about 5 years ago, I remember having those clic 3D gles with one blue lens and one red lens. Today I went to see the movie 'Coraline' another 3D movie, but the gles I recieved aren't like the old ones. The lenses on the new gles seem to be completely clear. How do these new ones work?