The Moon Illusion: Apparent Size and Visual Accommodation Distance.

Ground-Referenced Visual Orientation with Imaging Displays.

“…In this experiment visual accommodation was measured with a laser optometer and correlated with subjective judgments of the apparent size of the collimated moon projected just above the distant horizon. A systematic relationship (r -.9) was found between accommodation distance and the apparent size of the moon, a finding quite consistent with the hypothesis that accommodation varies with the locus of textural stimuli all of which are well beyond what is nominally though of as "optical infinity," as shown in (Iavecchia, et al, 1978).…”

“…An intriguing finding by Iavecchia et al (1978) was the subjects' differential accommodation to the various outdoor scenes--all at essentially 0 D. The scenes mathematically varied from 0.03-0.00 D, but this minuscule difference should not account for the gross variation observed. Was the eye actually responding to the minute changes in the dioptric distances of the scenes?…”

“…The operation of this system is described in greater detail by Iavecchia, Iavecchia, and Roscoe (1978) and by Benel (1979). It provides an absolute though subjective measure of visual accommodation in diopters (D), a scale inversely related to the distance to which the eye is focused (D 1 l/distance in meters).…”

Locus of the Stimulus to Visual Accommodation: Where in the World, or Where in the Eye?

“…However, since pilots flying airplanes by contact visual reference view objects at distances much greater than those tested, these findings needed to be extended and refined. This extension was undertaken by Iavecchia, Iavecchia, and Roscoe (1978).…”

Multifactor Determinants of Visual Accommodation as a Critical Intervening Variable in the Perception of Size and Distance: Phase I Report

“…In his fourth and final experiment in this series, Benel used the apparatus and one scene used in the earlier Iavecchia, Iavecchia, and Roscoe (1978) study to project an artificial moon and present a variable comparator for size judgment. A typical (dark fiberglass) screen, when presented, was placed at a distance of 1.33 m or 0.67 m or 0.44 m or 0.33 m. In conditions without the screen and across the four screen distances, the correlations between accommodation and apparent size were reliable (r = -0.56, p < .05; r = -0.76, p < .01, respectively).…”