- A simple test designed for stereopsis screening in children based on two principles, random dots and cylinder gratings.
- In binocular vision stereoscopic shapes are recognized.
- The images of the two eyes are separated by a system of fine parallel cylindrical strips. Beneath each cylinder there are two fine strips of pictures, one seen by the right, the other seen by the left eye. These two methods were combined for the first time in the Lang-Stereotest.

ADVANTAGES
- There are no glasses required which often distract a child.
- The patient’s eye movements are easily observed.
- Pocket sized.

Lang I: Disparity = Car 550", Star 600", Cat 1200"