Lang Sterotest #2
Easier to use than traditional Stereo / Binocular Vision tests – no glasses needed – lower cost.
A simple test designed for stereopsis screening in children based on 2 principles, random dots and cylinder gratings.
Schools world wide utilize the Lang Stereotest for screenings.
Pediatrician use for vision screening exams.
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.
Disparity = Moon 200″, Car 400″, Elephant 600″, Star monocular visible.