10182

# Binocular Disparity (Visual Depth Perception 7)

This Demonstration shows binocular and retinal disparity. Since our eyes are separated, they receive slightly different images, a "disparity". Mathematically, binocular disparity is the difference between the "convergence angles" . Binocular disparity is shown in degrees in orange. The scale is very small to exaggerate the angles in order to see what they measure at normal viewing distances.
Simple geometry shows that binocular disparity is also the signed difference of the separation angles measured counterclockwise from distraction to fixate for the two eyes, . With these sign conventions, the formula works in all cases.
The term "binocular disparity" refers to geometric measurements made external to the eye. The disparity of the images on the actual retina depends on factors internal to the eye, especially the location of the nodal points, even if the cross section of the retina is a perfect circle as in the model. The small brown segment shows the disparity between the images of the left and right eye. Notice that retinal disparity depends on the node location by sliding the "node percent" slider.

### DETAILS

Binocular disparity has been studied since Euclid, but was popularized by Wheatstone about 150 years ago with the invention of the "stereoscope".
Binocular disparity is constant on circles through the node points of the eyes, as we show in the Demonstration "Vieth–Müller Circles (Visual Depth Perception 8)" (see Related Links). The connection between depth and disparity is shown in the Demonstrations "Disparity, Convergence and Depth (Visual Depth Perception 10)" and "Binocular Disparity versus Depth (Visual Depth Perception 9)" (see Related Links).

### PERMANENT CITATION

 Share: Embed Interactive Demonstration New! Just copy and paste this snippet of JavaScript code into your website or blog to put the live Demonstration on your site. More details » Download Demonstration as CDF » Download Author Code »(preview ») Files require Wolfram CDF Player or Mathematica.

#### Related Topics

 RELATED RESOURCES
 The #1 tool for creating Demonstrations and anything technical. Explore anything with the first computational knowledge engine. The web's most extensive mathematics resource. An app for every course—right in the palm of your hand. Read our views on math,science, and technology. The format that makes Demonstrations (and any information) easy to share and interact with. Programs & resources for educators, schools & students. Join the initiative for modernizing math education. Walk through homework problems one step at a time, with hints to help along the way. Unlimited random practice problems and answers with built-in Step-by-step solutions. Practice online or make a printable study sheet. Knowledge-based programming for everyone.