Accommodation steps, target spatial frequency and refractive error

Strang, Niall C.; Day, Mhairi; Gray, Lyle S.; Seidel, Dirk

doi:10.1111/j.1475-1313.2011.00855.x

Cited by 14 publications

(24 citation statements)

References 57 publications

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“…If the participants stayed accommodated at near for a protracted time, this could produce myopic defocus on the contrast-sensitivity test pattern. However, the reported time required to change the accommodation response from 2.5 to 1 D is typically 0.25 to 0.30 seconds [49][50][51] and is similar for emmetropes and myopes [52][53][54] ; thus this is unlikely to account for the observed findings. Moreover, the contrast-sensitivity test was performed at 1 m, a distance close to the tonic accommodation level and a distance considered to usually induce high focusing accuracy.…”

Section: Generation Of Defocus Signalscontrasting

confidence: 38%

Near Work–Induced Contrast Adaptation in Emmetropic and Myopic Children

Yeo

Atchison

Lai

et al. 2012

Invest. Ophthalmol. Vis. Sci.

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Section: Generation Of Defocus Signalscontrasting

confidence: 38%

Near Work–Induced Contrast Adaptation in Emmetropic and Myopic Children

Yeo

Atchison

Lai

et al. 2012

Invest. Ophthalmol. Vis. Sci.

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“…Two accommodation modules based on a variation of the Badal optometer [25,26] were built to provide monocular accommodation step stimuli (Fig. 1).…”

Section: Methodsmentioning

confidence: 99%

Imaging and full-length biometry of the eye during accommodation using spectral domain OCT with an optical switch

Ruggeri

Uhlhorn

Freitas

et al. 2012

Biomed. Opt. Express

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An optical switch was implemented in the reference arm of an extended depth SD-OCT system to sequentially acquire OCT images at different depths into the eye ranging from the cornea to the retina. A custom-made accommodation module was coupled with the delivery of the OCT system to provide controlled step stimuli of accommodation and disaccommodation that preserve ocular alignment. The changes in the lens shape were imaged and ocular distances were dynamically measured during accommodation and disaccommodation. The system is capable of dynamic in vivo imaging of the entire anterior segment and eye-length measurement during accommodation in real-time.

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“…As such, blur perception is crucial to one's ability to navigate the world easily, and to accurately perform daily tasks such as reading and driving (Poulere, Moschandreas, Kontadakis, Pallikaris, & Plainis, 2013; Wood et al, 2014). Furthermore, it has been suggested that continuous retinal defocus may be a causative factor in refractive error development, although the evidence is conflicting (Cufflin, Mankowska, & Mallen, 2007; Flitcroft, 1998; Hess, Schmid, Dumoulin, Field, & Brinkworth, 2006; Norton, Siegwart, & Amedo, 2006; Rosenfield & Abraham-Cohen, 1999; Schmid, Iskander, Li, Edwards, & Lew, 2002; Smith III & Li-Fang, 1999; Smith III, Li-Fang, & Harwerth, 1994; Strang, Day, Gray, & Seidel, 2011; Taylor, Charman, O'Donnell, & Radhakrishnan, 2009; Vera-Diaz, Maiello, Kerber, Thorn, & Bex, 2015; Wallman & Winawer, 2004; Wildsoet & Wallman, 1995). …”

Section: Introductionmentioning

confidence: 99%

Blur perception throughout the visual field in myopia and emmetropia

et al. 2017

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We evaluated the ability of emmetropic and myopic observers to detect and discriminate blur across the retina under monocular or binocular viewing conditions. We recruited 39 young (23–30 years) healthy adults (n = 19 myopes) with best-corrected visual acuity 0.0 LogMAR (20/20) or better in each eye and no binocular or accommodative dysfunction. Monocular and binocular blur discrimination thresholds were measured as a function of pedestal blur using naturalistic stimuli with an adaptive 4AFC procedure. Stimuli were presented in a 46° diameter window at 40 cm. Gaussian blur pedestals were confined to an annulus at either 0°, 4°, 8°, or 12° eccentricity, with a blur increment applied to only one quadrant of the image. The adaptive procedure efficiently estimated a dipper shaped blur discrimination threshold function with two parameters: intrinsic blur and blur sensitivity. The amount of intrinsic blur increased for retinal eccentricities beyond 4° (p < 0.001) and was lower in binocular than monocular conditions (p < 0.001), but was similar across refractive groups (p = 0.47). Blur sensitivity decreased with retinal eccentricity (p < 0.001) and was highest for binocular viewing, but only for central vision (p < 0.05). Myopes showed worse blur sensitivity than emmetropes monocularly (p < 0.05) but not binocularly (p = 0.66). As expected, blur perception worsens in the visual periphery and binocular summation is most evident in central vision. Furthermore, myopes exhibit a monocular impairment in blur sensitivity that improves under binocular conditions. Implications for the development of myopia are discussed.

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Accommodation steps, target spatial frequency and refractive error

Abstract: These findings suggest that MYOs have some difficulty interpreting small changes in defocus to initiate or possibly fine tune a small accommodation response, however, when a correct accommodation step response is made, the MYOs accommodation plant responds in a similar manner to EMMs.

Cited by 14 publications

References 57 publications

Near Work–Induced Contrast Adaptation in Emmetropic and Myopic Children

Near Work–Induced Contrast Adaptation in Emmetropic and Myopic Children

Imaging and full-length biometry of the eye during accommodation using spectral domain OCT with an optical switch

Blur perception throughout the visual field in myopia and emmetropia

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