XpanD 3D System

The XpanD system uses active shutter glasses that alternately open and close the view for each eye. This very rapid flashing is synchronized with the screen, which alternately flashes the correct view for each eye.

The glasses are quite expensive—more than dolby's filter glasses and much more than simple polarized glasses. XpanD glasses required batteries and include electronic circuitry which can fail (unlike passive glasses that have no electronics).

The XpanD system is currently being used in cinemas around the world but is not as widespread as Dolby 3D or RealD. it is also marketed as a product for home theatre, gaming and other displays.