Citation

Smith G, Meehan JW, Day RH. Hum. Factors 1992; 34(3): 289-301.

Affiliation

Department of Optometry, University of Melbourne, Parkville, Victoria, Australia.

Copyright

(Copyright © 1992, Human Factors and Ergonomics Society, Publisher SAGE Publishing)

DOI

unavailable

PMID

1634241

Abstract

The apparent size of an object is diminished when accommodation of the eye moves inward to a position closer to the observer than to a viewed object. This phenomenon is called accommodation micropsia. Using schematic eyes, we investigated change in retinal image size caused by a change in accommodation. The use of schematic eyes is also discussed and is justified. The calculated magnitude of this diminution for four schematic eyes ranged from unity at infinity to a maximum of 0.98 (-2%) at about 12.0 diopters (D). For distances at which accommodation micropsia is typically observed (about 2.0 D), retinal minification is less than 0.997 (-0.3%). Thus changes in the size of the retinal image attributable to accommodation are virtually negligible when compared with the observed reduction of 3% to 33%. This suggests that accommodation micropsia is mediated almost entirely by processes other than those involving the optics of the eye.

Language: en