The effect of optotype presentation duration on acuity estimates revisited

Heinrich, Sven; Krüger, Katja; Bach, Michael

doi:10.1007/s00417-009-1268-2

Cited by 18 publications

(13 citation statements)

References 17 publications

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“…Note that the number of trials in the VA and CS tests used here was fixed, as was the dark adaptation time for each participant, so the relationship between task duration and performance is not a product of differences in the number of trials or the dark adaptation length. While the duration of optotype presentation has been previously documented to impact photopic performance, ours is the first study to show a strong effect under scotopic conditions [ 54 ]. In fact, our study shows a much stronger effect of task duration on scotopic performance than on photopic performance ( Fig 5 and S2 Fig ).…”

Section: Discussionmentioning

confidence: 99%

Individual Differences in Scotopic Visual Acuity and Contrast Sensitivity: Genetic and Non-Genetic Influences

et al. 2016

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Despite the large amount of variation found in the night (scotopic) vision capabilities of healthy volunteers, little effort has been made to characterize this variation and factors, genetic and non-genetic, that influence it. In the largest population of healthy observers measured for scotopic visual acuity (VA) and contrast sensitivity (CS) to date, we quantified the effect of a range of variables on visual performance. We found that young volunteers with excellent photopic vision exhibit great variation in their scotopic VA and CS, and this variation is reliable from one testing session to the next. We additionally identified that factors such as Circadian preference, iris color, astigmatism, depression, sex and education have no significant impact on scotopic visual function. We confirmed previous work showing that the amount of time spent on the vision test influences performance and that laser eye surgery results in worse scotopic vision. We also showed a significant effect of intelligence and photopic visual performance on scotopic VA and CS, but all of these variables collectively explain <30% of the variation in scotopic vision. The wide variation seen in young healthy volunteers with excellent photopic vision, the high test-retest agreement, and the vast majority of the variation in scotopic vision remaining unexplained by obvious non-genetic factors suggests a strong genetic component. Our preliminary genome-wide association study (GWAS) of 106 participants ruled out any common genetic variants of very large effect and paves the way for future, larger genetic studies of scotopic vision.

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Section: Discussionmentioning

confidence: 99%

Individual Differences in Scotopic Visual Acuity and Contrast Sensitivity: Genetic and Non-Genetic Influences

et al. 2016

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“…Although there has been minimal research examining the effect of duration on grating VA, the few studies that have been undertaken suggest that the utilization time for gratings is relatively short compared to letters (Graham & Cook, 1937; Keesey, 1960). Several factors have been proposed to account for the long utilization times recorded for letter VA tasks, but the explanation is not entirely clear (Baron & Westheimer, 1973; Heinrich, Kruger, & Bach, 2010; Ng & Westheimer, 2002)…”

Section: Introductionmentioning

confidence: 99%

The effect of exposure duration on visual acuity for letter optotypes and gratings

McAnany

2014

Vision Research

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This study compared the effects of exposure duration on letter and grating targets in a visual acuity (VA) task and determined if the broadband nature of letters accounts for their temporal summation characteristics. Log MAR (minimum angle of resolution) VA of five individuals (ages 25 to 36) was measured with a set of tumbling E optotypes for durations of 24 ms to 1 s. The Es were either unfiltered or low-pass filtered to determine the object frequencies (cycles per letter; cplE) mediating VA. The retinal frequencies mediating VA for the unfiltered E (cycles per degree; cpdE) were derived from the ratio of cplE to MAR. Values of cpdE were compared to threshold retinal frequency obtained with band-limited Es and gratings to further evaluate the effects of stimulus bandwidth. Both log MAR and log cplE for the unfiltered E decreased as duration increased up to approximately 260 ms, and were constant thereafter. VA also improved for gratings and band-pass filtered Es, but over a shorter time course (approximately 150 ms). The effect of duration on VA for the broadband E, Gabor, and band-pass filtered E was similar when the object frequencies mediating VA were included in the definition of VA by converting to cpdE. The results indicate that the pattern of temporal integration for the tumbling E is related to its broadband nature. Band-pass filtered letters can simplify the interpretation of VA because the object frequency information mediating VA is known exactly and is independent of duration and letter size.

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“…Additional difficulties arise from temporal instabilities. For instance, subjects may perceive near-threshold Landolt Cs as flipping or rotating [15].…”

Section: Discussionmentioning

confidence: 99%

“…However, a systematic improvement would manifest itself in the group mean. Some studies indeed found that the second test yields significantly higher acuity estimates than the first one, typically by a margin of 0.01-0.06 logMAR [e.g., [11][12][13][14][15][16]. However, similar other studies [e.g., 17,18] did not find a significant improvement in the second test, and a number of studies [e.g., [19][20][21][22] that assessed testretest reliability did not assess whether there was such a systematic sequence effect.…”

Section: Introductionmentioning

confidence: 99%

The dynamics of practice effects in an optotype acuity task

Heinrich¹,

Krüger²,

Bach³

2011

Graefes Arch Clin Exp Ophthalmol

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Feedback has a drastic effect on the magnitude and dynamics of the practice effect, which is not explained by simple familiarization with the test procedure. If feedback is not given, practice effects can be neglected in most clinical routine applications even when many test repetitions are performed. However, they may become relevant on a group level in clinical studies without an appropriate control.

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The effect of optotype presentation duration on acuity estimates revisited

Abstract: The results highlight the importance of standardizing presentation durations when high reproducibility is required.

Cited by 18 publications

References 17 publications

Individual Differences in Scotopic Visual Acuity and Contrast Sensitivity: Genetic and Non-Genetic Influences

Individual Differences in Scotopic Visual Acuity and Contrast Sensitivity: Genetic and Non-Genetic Influences

The effect of exposure duration on visual acuity for letter optotypes and gratings

The dynamics of practice effects in an optotype acuity task

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