How to do stereopsis test ?
A. Equipment needed for check the stereopsis
1. Polaroid glasses
2. Stereo target
3. Overhead lamp
B. Set-up
1. Patient wears polaroid glasses over his habitual Rx
2. Patient holds stereo target at 40 cm
3. Overhead lamp is directed toward the target
C. Step-by-step procedure
1. Direct patient attention to the first set of circles. Ask patient in target number one, which of these circles appear closest to you? Which circle appears to be floating above the plane of the page?
2. Continue testing until patient gives two consecutive incorrect answers.
3. If the patient is unable to identify any of the circles correctly, repeat steps 1 and 2 using the animal targets and then repeat using the circle target.
4. If the patient is unable to identify any of the animals correctly, show the patient.the large targets and ask him or her to identify the geometric figures (s) he sees, or show the patient the fly and ask him or her to pinch the wings of the fly.
D. Recording
1. Write 'Stereo at N' (Near).
2. If done without correction, record se; if done with correction, record cc.
3. Record the amount of stereopsis in seconds of arc (taken from the instructions that t come with the stereo test) for the last correct response the patient gave before two incorrect responses.
4. Record the name of the test used.
E. Examples
Stereo at N sc 40 sec Titmus
Stereo at N sc 20 sec
Randot Stereo at N sc 3000 sec (stereo fly)