Dynamic Accommodation Responses Following Adaptation to Defocus

Cufflin, Matthew P; Mallen, Edward A. H.

doi:10.1097/opx.0b013e3181886fda

Cited by 11 publications

(13 citation statements)

References 41 publications

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“…Following a wash‐out period without blur adaptation, accommodation response parameters returned to the pre‐adaptation levels. Cufflin and Mallen observed increases in accommodation response time to stepwise stimulus changes following blur adaptation. There was also an increase in accommodation response phase lag when tracking a sinusoidally moving accommodative stimulus.…”

Section: Quantifying the Effects Of Blur Adaptationmentioning

confidence: 97%

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Blur adaptation: clinical and refractive considerations

Cufflin

Mallen

2020

Clinical and Experimental Optometry

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The human visual system is amenable to a number of adaptive processes; one such process, or collection of processes, is the adaptation to blur. Blur adaptation can be observed as an improvement in vision under degraded conditions, and these changes occur relatively rapidly following exposure to blur. The potential important future directions of this research area and the clinical implications of blur adaptation are discussed.

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Section: Quantifying the Effects Of Blur Adaptationmentioning

confidence: 97%

“…High‐contrast logMAR VA charts have been used widely in the measurement of blur adaptation changes during and following exposure to defocus . VA with myopic defocus in place is measured to provide an insight into the changes in resolution that occur during blur adaptation.…”

Section: Quantifying the Effects Of Blur Adaptationmentioning

confidence: 99%

Blur adaptation: clinical and refractive considerations

Cufflin

Mallen

2020

Clinical and Experimental Optometry

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“…In contrast, other studies (Vera-Diaz et al, 2004; observed that a 45-min long blur adaptation period did not change steady-state accommodative responses or the accommodative stimulus-response function gradient of both emmetropes and myopes. However, it was observed (Cufflin and Mallen, 2008) that adaptation to defocus caused increased accommodation for a dynamic target, and subsequently increased the response time and phase lag of emmetropes and myopes.…”

Section: Introductionmentioning

confidence: 99%

Effect of Cycloplegia on Blur Perception Thresholds as Measured by Source Method

Petrova

Lulle

Cikmacs

et al. 2017

Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences.

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One of the advantages of a source method over observer method in blur perception measurements is better control of a stimulus blur level, which is achieved with computerised image processing unlike the observer method that requires optical defocusing of the observer. The aim of this study was to determine if paralysation of accommodation has effect on blur perception thresholds, thereby evaluating its necessity in such experiments. Blur perception thresholds (just noticeable blur, clear image, recognition, and non-resolvable blur thresholds) were evaluated with (using cycloplegia) and without paralysed accommodation to determine effect on blur perception. A computerised low-pass spatial frequency filter was used to process images of Landolt rings and gradually increase the blur level from the stage of clear image to the stage of unrecognisable orientation of Landolt ring opening. Ascending and descending psychophysical methods were used to evaluate the previously mentioned blur perception thresholds. Results for 10 participants revealed no significant effect of cycloplegia on any of the determined blur perception thresholds. Therefore, it may be considered that blur perception measurements with source method can be done without cycloplegia.

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“…11,14–18 Adaptation to blur has been shown to modify other oculomotor responses such as the accommodative response. 2,19 Adaptation to blurred text, as measured with similar procedures, may also improve the ability to read blurred text. 20 …”

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confidence: 99%

Blur Adaptation to Central Retinal Disease

Vera-Díaz

Woods

Peli

2017

Invest. Ophthalmol. Vis. Sci.

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PurposeThe long-term, low-resolution vision experienced by individuals affected by retinal disease that causes central vision loss (CVL) may change their perception of blur through adaptation. This study used a short-term adaptation paradigm to evaluate adaptation to blur and sharpness in patients with CVL.MethodsA variation of Webster's procedure was used to measure the point of subjective neutrality (PSN). The image that appeared normal after adaptation to each of seven blur and sharpness levels (PSN) was measured in 12 patients with CVL (20/60 to 20/320) and 5 subjects with normal sight (NS). Patients with CVL used a preferred retinal locus to view the images. Small control studies investigated the effects of long-term and medium-term (1 hour) defocus and diffusive blur.ResultsAdaptation was reliably measured in patients with CVL and in the peripheral vision of NS subjects. The shape of adaptation curves was similar in patients with CVL and both central and peripheral vision of NS subjects. No statistical correlations were found between adaptation and age, visual acuity, retinal eccentricity, or contrast sensitivity. Long-term blur experience by a non-CVL myopic participant caused a shift in the adaptation function. Conversely, medium-term adaptation did not cause a shift in the adaptation function.ConclusionsBlur and sharp short-term adaptation occurred in peripheral vision of normal and diseased retinas. In most patients with CVL, neither adaptation nor blur perception was affected by long-term attention to peripheral low-resolution vision. The impact of blur/sharp adaptation on the benefit of image enhancement techniques for patients with CVL is discussed.

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Dynamic Accommodation Responses Following Adaptation to Defocus

Abstract: Adaptation to a degraded stimulus causes an increased level of accommodation for dynamic targets moving towards an observer and increases response times and phase lags. It is suggested that the contrast constancy theory may explain these changes in dynamic behavior.

Cited by 11 publications

References 41 publications

Blur adaptation: clinical and refractive considerations

Blur adaptation: clinical and refractive considerations

Effect of Cycloplegia on Blur Perception Thresholds as Measured by Source Method

Blur Adaptation to Central Retinal Disease

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