The TY-EW3D2MU 3D Active Shutter Eyewear (Medium) from Panasonic are glasses that work by responding to a sync signal transmitted by compatible Panasonic HDTVs. Highly precise control completely closes the shutters for both eyes at the instant that the images change for the left and right eyes. Many times per second, faster than the eye can perceive, the HDTV shows the image meant for the left eye and then the image for the right eye. The glasses alternately block first one eye then the other. It all happens so fast that your brain sees a 3D image.
The 3D Eyewear can also be comfortably worn right over ordinary prescription glasses. The glasses are compatible with the TC-P54VT25, TC-P65VT25, TC-P58VT25, TC-46PGT24, TC-P50VT20, TC-P42GT25, TC-P50VT25, and the TC-P50GT25.