Pupil size, mean accommodation response and the fluctuations of accommodation

Abstract

Summary We wished to determine how pupil size and mean accommodation response level interact to influence the fluctuations of accommodation. A dynamic infra‐red optometer was used to record accommodation responses while subjects viewed a steady target at two stimulus levels (1.5 and 3 D) through four pupils (1, 2, 4 and 6 mm). It was found for most subjects that the fluctuations of accommodation increase at higher mean accommodation response levels, and small pupils lead to an increase in the low frequency (but not the high frequency) fluctuations of accommodation. The effects of mean accommodation response are independent of pupil size, and the effects of pupil size are independent of mean response level.

Multifocal Pupillographic Perimetry With White and Colored Stimuli

“…46 The cortical inputs to the pupil likely drive the accommodative response of the pupils. 47 Cortical-like sensitivity to interocular disparity is certainly present in pupillary responses. 48 Although longitudinal chromatic aberration seems to be a major driver of the sign accommodation 49 luminance blur alone is a sufficient accommodative cue, 50 and the effects of longitudinal chromatic aberration are thought to be governed by both color and luminance channels.…”

The relationship between object spatial profile and accommodation microfluctuations in emmetropes and myopes

“…These theories are supported by findings showing that the magnitude of the accommodation microfluctuations vary systematically with target characteristics such as target luminance (Day, Seidel, Gray, & Strang, 2009a;Gray, Winn, & Gilmartin, 1993b), the spatial frequency (SF) content of the stimulus (Niwa & Tokoro, 1998) as well as with variations in ocular depth of focus induced by alterations in pupil size (Campbell et al, 1959;Day et al, 2009a;Gray, Winn, & Gilmartin, 1993a;Stark & Atchison, 1997).…”

“…Under conditions where depth of focus is altered using artificial pupils, microfluctuations are seen to increase systematically when depth of focus is increased (Atchison, Charman, & Woods, 1997;Campbell, 1957;Charman & Whitefoot, 1977;Day et al, 2009a;Ogle & Schwartz, 1959;Stark & Atchison, 1997). The increase in depth of focus for pupils G2 mm in diameter is caused by restricting image formation to paraxial rays only, and it is thought that any changes in the contrast gradient of the image modulated by the microfluctuations cannot be detected by the accommodation controller (Day et al, 2009a).…”

Dynamic Accommodation Responses to Stationary Colored Targets

“…44 Targets were presented with a Maxwellianview Badal optometer attached to the Ophthalmetron. 44 To test the signal-to-noise ratio of the instrument, 10 recordings were taken from the model eye supplied with the Ophthalmetron, and 5 and 9 recordings were taken from two cyclopleged human eyes (1 drop of 1% cyclopentolate; subjective amplitude of accommodation, Ͻ0.4 D).…”

“…44 Targets were presented with a Maxwellianview Badal optometer attached to the Ophthalmetron. 44 To test the signal-to-noise ratio of the instrument, 10 recordings were taken from the model eye supplied with the Ophthalmetron, and 5 and 9 recordings were taken from two cyclopleged human eyes (1 drop of 1% cyclopentolate; subjective amplitude of accommodation, Ͻ0.4 D). The response was sampled at 35.97 Hz for 14.2 s. The root-mean-square level in the model eye was 0.024 D, and the root-mean-square levels in the two cyclopleged eyes were 0.06 and 0.10 D, indicating little influence of noise on optometer readings.…”