The 3D glasses that are used with Toshiba computer are Active 3D. That is the lens in the glasses consists of LCD screens that 'actively' shutter open and close 120 times per second in order to give different screen views to each eye.

There are also Passive 3D glasses which use polarized lens to give the 3D effect. The polarized glasses are the type of glasses you would get at the movie theatre when when watching a 3D movie.

Because the Active 3D glasses use LCD screens for the lens, they need a battery to power the shutter action on the LCD screens. The Toshiba 3D glasses use a rechargeable battery for the power. The battery is recharged using a USB cable that is included with the 3D glasses. The 3D glasses can not be used while the battery is being charged.

Next to the USB connector on the 3D glasses is a small amber LED. The amber LED will flash while being charged. Once the battery is fully charged the amber LED will stay solid.

On top of the left arm of the 3D glasses is the on-off switch. Right next to the on-off switch is an indicator LED. Green means that the battery is charged. A flashing red LED means that there is 2 hours or less of battery power available. No LED light means that the battery needs to be recharged. After 30 seconds the LED turns off.

In order to synchronize the LCD lens shutter action with what is being displayed ont computer's screen, there is an IR sensor just to the leftt of the left lens. Putting finger over the sensor will prevent you from seeing the screen in 3D. And so will anything else that gets between IR sensor on the 3D glasses and the IR transmitter on the computer.