The Lang Stereo Test is an easy to use screening test designed for early detection of problems with stereoscopic vision in children and adults without the need for dissociating glasses.
It is suitable for children as young as 30 months by identifying pictures on a card. The test is simple, quick to use and is fun for the child.
Each card shows three objects to be recognised which assess three different levels of stereo acuity. There are two versions of the test. The Lang Stereo Test 2 contains a monocular star in addition that can be seen with only one eye.
LANG 1 (cat, car, star) measures from 1200 to 550 seconds of arc. LANG 2 (elephant, car, moon) measures from 600 to 200 seconds of arc.
This simple test designed for stereopsis screening in children based on 2 principles: random dots and cylinder gratings.
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.
Schools world wide are utilizing the Lang Stereotest for vision screenings.
Pediatrician use for vision screening exams.
In binocular vision stereoscopic shapes are recognized.