Instrument myopia conceptions, misconceptions, and influencing factors.

The literature on instrument myopia is reviewed, with the review organized around three principal objectives. One is to describe and discuss various factors that may influence the degree to which instrument myopia is manifested, including monocular vs. binocular viewing, age, direction of focus, illumination level, fatigue, magnification, astigmatic variations, optical decentration, perceived proximity of the target and peripheral surround, and experience. The second objective is to discuss the intermediate resting state conception of accommodation, its application to instrument myopia, and its strengths and weaknesses as applied to the available literature. The third objective is to summarize the salient problems in the instrument myopia literature, and to present a set of recommendations for guiding future work.