Anaglyphic 3D images require you to wear red/cyan glasses (viewers) like those pictured above. The red lens normally goes over your left eye.
Important: 3-D viewers are available from many sources. Be aware that not all viewers are created equal and some give much better results than others. Factors such as the accuracy of the colour gels and the amount of light which they let through determine how well the 3D effect will work. If you find that the 3D effect is not working, it may be because your viewers are poor quality.
We recommend the viewers available at acb3d.com. These include very high-quality gels correctly calibrated to anaglyphic viewing.