(product code: 20DP)
in the "20 base out prism test".
- One of the
easiest, fastest and most effective ways of
screening for binocular vision in
- If the child is not cooperative enough to conduct
other tests, a 20 dioptre base-out prism is put in front of one eye
while shining a penlight (or even using a captivating fixation target). If the eyes adjust to the prism and the
corneal reflexes become straight, fusion is present which proves the
existence of binocular vision.
useful for any optometrist / ophthalmologist / orthoptist.