major amblyoscope

ma·jor am·bly·o·scope

an amblyoscope in which intensity of illumination as well as targets may be varied.

amblyoscope, Worth 

A modified haploscope introduced by Worth, consisting of two angled tubes held in front of the eyes which present a different image to each eye, and which can be turned to any degree of convergence or divergence. Using various images (slides), the instrument can be used to measure the angle of deviation and vergence amplitudes, and to investigate retinal correspondence, fusion, suppression and stereopsis. If the instrument is incorporated into a table, it is called a major amblyoscope of which there are various types called Synoptiscope or Synoptophore.