Beginning of Essay
Single Image Random Dot (SIRDS) are not only a lot of fun, but they demonstrate many of the properties of stereopsis. "Stereopsis" means that each eye sees a slightly different image, also known as three dimensional or 3D. Stereopsis is essential for our percept ....

Middle of Essay
.... dots that fall within the blue circle. (fig. 2). Next, he created a new rectangle identical to the original rectangle, except that the dots within the small shape have been shifted to the left. (fig. 3). When the two rectangles are viewed together as a stereo pair, the image of the circle appears to float above the background. (fig. 4). In 1979 Christopher Tyler discovered that the offset scheme could be applied to a single image. This was the birth of the single image random dot stereogram (fig. 5). Depth perception depends on having two eyes. Most people who have depth perception can see a Magic Eye image. P ....