The technologies, which are originally developed mainly in mainframe computers as a core part of the "virtual reality" environment, are growing very rapidly with popularity gained in the personal computer domain as well. You need to wear a pair of 3D shutter glasses to visualise the  3D pictures and 3D videos given below.  With the signal (via electrical wire or infra-red) emitted from the computer which is synchronized with the images/videos displayed on the computer monitor, the right-hand and left-hand shutter glasses will turn on and off sequentially to let the observer view the right-hand and left-hand images of the objects or videos.  As the refresh rate is fairly high (>60 frames per second), our human brain will treat the images from the two eyes to arrive simultaneously and combine them to form the 3D images which have the depth clues. Almost all people can see the 3D effects without difficulties but prolonged viewing may cause some unpleasant feeling to some people.