Depth of Focus and Amplitude of Accommodation Through Trifocal Glasses

MANY STUDIES have been made of the "amplitude of accommodation" in presbyopia, but there has been little attempt to measure its component parts. Since it is a complex of active accommodation, depth of focus, and interpretation or suppression of blur fringes, the old term should be changed to "range of clear vision." Many textbooks contain figures for depth of focus of the human eye derived mathematically from the dimensions of a foveal cone, but to my knowledge there are no subjective data except those of Ogle1(1927) and Burian and Schubert2(1936). They used the same method and obtained results similar to those to be described here.