Chromatic-Spatial Vision of the Aging Eye

Werner, John S.; Delahunt, Peter B.; Hardy, Joseph L.

doi:10.1007/s10043-004-0226-9

Cited by 10 publications

(2 citation statements)

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“…Although these findings demonstrate losses in detection and discrimination for stimuli at threshold, only minor deficits are found when the same stimuli are above threshold (Werner, Delahunt, & Hardy, 2004). At higher levels of S cone excitation, chromatic discrimination losses wane (Schefrin et al, 1995).…”

Section: Introductionmentioning

confidence: 63%

Aging and blur adaptation

et al. 2007

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Color appearance remains remarkably stable in the aging visual system despite large changes in the spectral distribution of the retinal stimulus and losses in chromatic sensitivity (P. B. Delahunt, J. L. Hardy, K. Okajima, & J. S. Werner, 2005; J. S. Werner, 1996). This stability could reflect adaptive adjustments in peripheral or central chromatic mechanisms that compensate for sensitivity losses in senescence. We asked whether similar compensatory adjustments play a role in maintaining spatial vision--and whether the adaptation itself shows changes with aging-by examining the effects of adaptation on judgments of image focus. Perceptual aftereffects following adaptation to a uniform field and blurred or sharpened images were compared between younger adults and older observers. Subjects adapted to a sequence of blurred or sharpened images for 120 s, and a two-alternative forced-choice staircase task was used to vary the filter exponent of the test to define the subjective point of best focus. There was a small but significant difference between younger and older observers in the level perceived as best focused in all three adaptation conditions, possibly reflecting differences in the ambient blur level the groups are routinely exposed to. However, the magnitude of the blur aftereffect did not differ between the two age groups. These results suggest that although there may be small differences in the long-term adaptation to blur, younger and older observers do not differ in the strength of adaptation to transient changes in blur. The neural processes mediating adaptation to blur thus appear to remain largely intact with aging.

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Section: Introductionmentioning

confidence: 63%

Aging and blur adaptation

et al. 2007

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“…Human color vision results from complex neurophysiologic renormalization processes which address change in transmittance of ocular media, variations of luminance and spectral composition [ 46 – 49 ]. This results in color constancy with varying illumination conditions, and in a relatively stable suprathreshold color perception with minimal effect of aging.…”

Section: Photoreception In Pseudophakic Eyes With the Blue Light-filtmentioning

confidence: 99%

Recent studies provide an updated clinical perspective on blue light-filtering IOLs

Davison

Patel

Cunha

et al. 2011

Graefes Arch Clin Exp Ophthalmol

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BackgroundRecent reviews of blue light-filtering intraocular lenses (IOLs) have stated their potential risks for scotopic vision and circadian photoentrainment. Some authors have challenged the rationale for retinal photoprotection that these IOLs might provide. Our objective is to address these issues by providing an updated clinical perspective based on the results of the most recent studies.MethodsThis article evaluates the currently available published papers assessing the potential risks and benefits of blue light-filtering IOLs. It summarizes the results of seven clinical and two computational studies on photoreception, and several studies related to retinal photoprotection, all of which were not available in the previous reviews. These results provide a clinical risk/benefit analysis for an updated review for these IOLs.ResultsMost clinical studies comparing IOLs with and without the blue light-filtering feature have found no difference in clinical performance for; visual acuity, contrast sensitivity, color vision, or glare. For blue light-filtering IOLs, three comparative clinical studies have shown improved contrast sensitivity and glare reduction; but one study, while it showed satisfactory overall color perception, demonstrated some compromise in mesopic comparative blue color discrimination. Comparative results of two recent clinical studies have also shown improved performance for simulated driving under glare conditions and reduced glare disability, better heterochromatic contrast threshold, and faster recovery from photostress for blue light-filtering IOLs. Two computational and five clinical studies found no difference in performance between IOLs with or without blue light-filtration for scotopic vision performance and photo entrainment of the circadian rhythm. The rationale for protection of the pseudophakic retina against phototoxicity is discussed with supporting results of the most recent computational, in-vitro, animal, clinical, and epidemiological investigations.ConclusionsThis analysis provides an updated clinical perspective which suggests the selection of blue light-filtering IOLs for patients of any age, but especially for pediatric and presbyopic lens exchange patients with a longer pseudophakic life. Without clinically substantiated potential risks, these patients should experience the benefit of overall better quality of vision, reduced glare disability at least in some conditions, and better protection against retinal phototoxicity and its associated potential risk for AMD.Electronic supplementary materialThe online version of this article (doi:10.1007/s00417-011-1697-6) contains supplementary material, which is available to authorized users.

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