Accommodation function of the human eye

On voluntary ocular accommodation

“…to bring light from near objects into focus on the retina. At this time we have limited understanding of the nature of the adequate stimulus for accommodation (Campbell & Westheimer, 1959) and the extent to which the response is innate (reflexive) or learned (Fincham, 1951;Heath, 1956;Campbell, 1959;Borish, 1970;Toates, 1972). It is therefore desirable to better understand the conditions under which accommodation may be induced.…”

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

“…Rods and cones transduce electromagnetic radiation into neural impulses through photochemical processes mediated by their respective rhodopsin families of pigments. Toates (1972), in his classic tutorial, points out that the most central region of foveal cones (corresponding to about 30 min. of visual angle) have been strongly implicated as primary agents in the accommodative reflex under photopic and, less effectively, mesopic conditions (Campbell, 1954;Crane, 1966;Fincham, 1953a;Wald, 1967).…”

“…There has also existed a growing body of (no longer controversial) evidence that the sympathetic nervous system (SNS) is a generalized agent in extension (Cogan, 1937;Toates, 1972;Gilmartin, 1986). Jose, Poise, and Holden (1984), in their 3rd chapter, provide a concise discourse on both the pharmacological and anatomical specifications bearing on both the PNS and SNS innervations of the human visual system.…”

The effects of ingested alcohol on accommodation

“…Accommodation and vergence interact in complex ways that have been a source of speculation for years (Alpern, 1958;Carroll, 1982;Fincham & Walton, 1957;Flom, 1955;Miller, 1980;Morgan, 1944Morgan, , 1968Toates, 1970Toates, , 1972. As several writers have pointed out (e.g., Alpern, 1969;Cohen & Alpern, 1969;Olge, Martens, & Dyer, 1967), alcoholinduced heterophorias might be the effect of changes in accommodation, resulting in parallel changes in accommodative vergence.…”

“…DF refers to accommodation in the absence of an external stimulus, as is the case in total darkness (e.g., Leibowitz, Hennessy, & Owens, 1975;Leibowitz & Owens, 1975a, 1975bMiller, 1978). DF is taken as an estimate of the intermediate resting state of accommodation, which may represent a neuromuscular balance between sympathetic and parasympathetic influences (e.g., Cogan, 1937;Leibowitz, 1976;Leibowitz 407 Copyright 1985 Psychonomic Society, Inc. Owens, 1978;Melton, Purnell, & Brecher, 1955;Miller & LeBeau, 1982;Morgan, 1957;Schober, 1954;Toates, 1970Toates, , 1972. DF may be seen as reflecting a basic tonus, affecting accommodation in a variety of visually impoverished stimulus situations (Alpern & David, 1958;Johnson, 1976;Leibowitz & Owens, 1975a, 1975bMorgan, 1957).…”