Round the lamp he placed a microscope, diopter, scales, plumb bobs, and a sounding rod, whose varnished brasses diffused a warm sunlight yellow.
To find the refraction that produced the sharpest retinal images, we varied the vergence of the source over a range of 21 diopters (28.4 to 12.6 diopters).
The images on the left, labelled hyperopic, are for a converging incoming bundle of rays (18.4 diopters) and those on the right are for a diverging bundle (28.4 diopters).
The animal shown with squares was 5 diopters more hyperoptic (and the animal shown with circles was 10 diopters more hyperopic) than the animal shown with the triangles.
All four of the lens-reared monkeys developed natural hyperopic anisometropia of greater than 2 diopters.
All subjects were in excellent ocular health and in excellent general health, and no subjects had myopia$ 5 diopters.
The resulting esotropia was moderate, ranging from 10 to 25 prism diopters.
We accept that this, in addition to the fact the measuring light is a 632.7-nm laser, may explain the 10– diopters of hyperopia.
