Most animals have two eyes. Each eye provides a different view of the world, but the brain automatically combines them when both eyes are open. By combining the images viewed with both eyes the brain creates a three dimensional view.
Color filters only allow light of the same color to pass through them, so the red filter only allows red light to pass through it and the green filter only allows green light through. A red object is seen as red because it reflects red light and absorbs all other colors of light. If a red object is viewed through a green filter it will appear dark or black because the red light it reflects is not allowed to pass through the green filter. If a red object is viewed through a red filter it will be difficult to see. Since only red light is allowed through the red filter, the light from the red object will blend in with the other red light the filter allows through. Wearing the 3-D glasses thus results in a situation in which each eye sees a drastically different view of the same object. The eye covered with red cellophane only sees green images and the eye covered with green cellophane only sees red.
Three-dimensional pictures are created by printing part of the image in red and superimposing another part of the image in green. Each eye sees a different part of the picture when the 3-D glasses are used because the filters allow different colors to reach each eye. The brain combines the two images, which provides the illusion of depth and allows three-dimensional viewing from a two-dimensional image.
"Science for Fun: Light and Color," Gary Gibson, Copper Beach Books, Brookfield, 1993, p. 18-19.
"Science School," M. Manning and B. Granstorm, Kingfisher, 1998, p. 34-35.
© S. Olesik, WOW Project, Ohio State University, 2000.
Print Version Light Experiments Main Experiments Page Home