A haploscope is an optical device for presenting one image to one eye and another image to the other eye. The word derives from two Greek roots: haploieides, single and skopeo, to view. The word is often used interchangeably with stereoscope, but it is more general than that.

What is haploscopic principle?

Principle  Haploscopic principle it is based on the principle of division of physical space in to two separate area of visual space each of which is visible to one eye only.

What is a Synoptophore used for?

The synoptophore was used to measure torsional interocular disparity. This, in turn, was used to compute how much the angle between the Listing's plane (LP) of the two eyes changes as a function of the vergence angle.