Shuttered glasses contain shutters in them that open and close. This allows the right eye to see the image that is meant for it while closing when the image for the left eye is displayed. This opening and closing happens 120 times a second, so fast that your eye won’t even realize it. As far as your eyes are concerned there is a constant image going into each eye at the rate of 60 frames per second. According to your brain there is depth to the image because each image is slightly different, just like you would normally see.
Shuttered glasses require battery power in order to open and close. Each set of glasses must be synchronized with a transmitter on the 3D TV so they know when to open and close.
