Binocular single vision is tested by -

Synoptophore (major amblyoscope) consists of two tubes, having a right-angled bend, mounted on a base. Each tube contains a light source for illumination of slides and a slide carrier at the outer end, a reflecting mirror at the righth-angled bend and an eyepiece of +6.5 D at the inner end. The two tubes can be moved separately or together by means of knobs around a semicircular scale. Synoptophore tests for sensory functions include: Estimation of grades of binocular vision Detection of normal / abnormal retinal correspondence (ARC) Neutral density filter test.