Quick answer
A random dot stereogram is a pair of dot patterns that creates a sense of depth when each eye sees one of them. The hidden shape only appears when both eyes work together. In vision therapy, RDS exercises help improve stereoacuity, the ability to see fine 3D depth, and vergence, how the eyes turn together.
Random-dot stereogram (RDS) is a stereo pair of images of random dots which when viewed with the aid of a stereoscope, or with the eyes focused on a point in front of or behind the images, produces a sensation of depth, with objects appearing to be in front of or behind the display level.
Used for therapeutic purpose, the patient goes through these modules in the form of exercises and when they complete these exercises they improve in stereoacuity and vergence.
Medically reviewed by Amit Sahni (B.Optom), Co-founder and COO of CureSee, on 19 October 2026. This article is general information about eye health, not medical advice. Please talk to your eye doctor about your own eyes and treatment.