Regulation of pupil size in natural vision across the human lifespan

Royal Society Open Science, Journal Year: 2024, Volume and Issue: 11(6)

Published: June 1, 2024

Vision is mediated by light passing through the pupil, which changes in diameter from approximately 2 to 8 mm between bright and dark illumination. With age, mean pupil size declines. In laboratory experiments, factors affecting can be experimentally controlled. How reflects change retinal input visual environment under natural viewing conditions unclear. We address this question a field experiment ( N = 83, 43 female, 18–87 years) using custom-made wearable video-based eye tracker with spectroradiometer measuring near-corneal spectral irradiance. Participants moved indoor outdoor environments varying spectrum engaged range of everyday tasks. Our data confirm that light-adapted determined level, better model fit melanopic over photopic units, it decreased increasing yielding steeper slopes at lower levels. found no indication sex, iris colour or reported caffeine consumption affects size. exploratory results point role photoreceptor integration controlling steady-state The provide evidence for considering age personalized lighting solutions against use illuminance alone assess impact real-world conditions.

Language: Английский

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Increased brightness assimilation in rod vision

iScience, Journal Year: 2025, Volume and Issue: 28(2), P. 111609 - 111609

Published: Jan. 5, 2025

Our visual system uses contextual cues to estimate the brightness of surfaces: can shift toward (assimilation) or away from (contrast) surroundings. We investigated induction at different light levels and found a potential influence rod photoreceptors on induction. then used novel tetrachromatic display generate stimuli differentially exciting rods cones fixed adaptation level. Under vision, assimilation was enhanced while contrast not altered in comparison cone vision. ruled out that this effect mediated by low resolution night findings suggest vision affects high-level interpretation scenes results differences but contrast. imply employs more perceptual inferences under than solve ambiguities complex spatial displays.

Language: Английский

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Quadrant Field Pupillometry Detects Melanopsin Dysfunction in Glaucoma Suspects and Early Glaucoma

Scientific Reports, Journal Year: 2016, Volume and Issue: 6(1)

Published: Sept. 13, 2016

Abstract It is difficult to detect visual function deficits in patients at risk for glaucoma (glaucoma suspects) and early disease stages with conventional ophthalmic tests such as perimetry. To this end, we introduce a novel quadrant field measure of the melanopsin retinal ganglion cell mediated pupil light response corresponding typical glaucomatous arcuate defects. The melanopsin-mediated post-illumination (PIPR) was measured 46 different including suspects compared healthy group 21 participants no disease. We demonstrate that superonasal PIPR differentiated from controls fair (AUC = 0.74) excellent 0.94) diagnostic accuracy, respectively. provides linear functional correlate structural nerve fibre thinning patients. This first report stimulation detects dysfunction pre-perimetric may have future implications treatment decisions suspects.

Language: Английский

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The Method of Silent Substitution for Examining Melanopsin Contributions to Pupil Control

Frontiers in Neurology, Journal Year: 2018, Volume and Issue: 9

Published: Nov. 27, 2018

The human pupillary light response is driven by all classes of photoreceptors in the eye-the three cones, rods, and intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing photopigment melanopsin. These photoreceptor have distinct but overlapping spectral tuning, even a monochromatic with wavelength matched to peak sensitivity given will stimulate photoreceptors. method silent substitution uses pairs lights ("metamers") selectively class while keeping activation others constant. In this primer, we describe provide an overview studies that used it examine inputs response.

Language: Английский

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Rhodopsin and Melanopsin Contributions to the Early Redilation Phase of the Post-Illumination Pupil Response (PIPR)

PLoS ONE, Journal Year: 2016, Volume and Issue: 11(8), P. e0161175 - e0161175

Published: Aug. 22, 2016

Melanopsin expressing intrinsically photosensitive Retinal Ganglion Cells (ipRGCs) entirely control the post-illumination pupil response (PIPR) from 6 s post-stimulus to plateau during redilation after light offset. However, photoreceptor contributions early phase of PIPR (< post-stimulus) have not been reported. Here, we evaluated (0.6 5.0 s) by measuring spectral sensitivity criterion amplitude in 1 pulses at five narrowband stimulus wavelengths (409, 464, 508, 531 and 592 nm). The retinal irradiance producing a was normalised peak fitted either single photopigment nomogram or combined melanopsin rhodopsin nomograms with +L+M cone photopic luminous efficiency (Vλ) function. We show that times ≥ 1.7 offset is best described nomogram. At < s, shifts longer (range: 482 498 nm) nomogram, major rhodopsin. This first report line electrophysiological findings ipRGC rod signalling cessation stimuli provides cut-off time for isolating specific function healthy diseased eyes.

Language: Английский

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Photoreceptor inputs to pupil control

Journal of Vision, Journal Year: 2019, Volume and Issue: 19(9), P. 5 - 5

Published: Aug. 15, 2019

The size of the pupil depends on light level. Watson and Yellott (2012) developed a unified formula to predict from luminance, field diameter, age, number eyes. Luminance reflects input L M cones in retina but ignores contribution intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing photopigment melanopsin, which are known control pupil. We discuss role melanopsin controlling by reanalyzing an extant data set (Bouma, 1962). confirm that melanopsin-weighted quantities, conjunction with Yellott's formula, adequately model intensity-dependent size. contributions other photoreceptors into control.

Language: Английский

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Luminance and chromatic signals interact differently with melanopsin activation to control the pupil light response

Journal of Vision, Journal Year: 2016, Volume and Issue: 16(11), P. 29 - 29

Published: Sept. 30, 2016

Intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin. These receive afferent inputs from rods and cones, which provide to postreceptoral visual pathways. It is unknown, however, how melanopsin activation integrated with signals control pupillary light reflex. This study reports human flicker responses measured using stimuli generated a five-primary photostimulator that selectively modulated melanopsin, rod, S-, M-, L-cone excitations in isolation, or combination produce signals. We first analyzed adaptation behavior of rod cones Second, we determined by testing cone luminance, chromatic blue-yellow, red-green were processed magnocellular (MC), koniocellular (KC), parvocellular (PC) pathways, respectively. A combined response was also measured. The relative phase varied respect phase. results showed for all conditions weaker than typical Weber adaptation. Melanopsin linearly S-cone, inputs, suggesting locus integration MC KC retinal. contribution phasic pupil lower luminance contributions, but much higher S-cone contributions. Chromatic modulation interacted nonlinearly as described "winner-takes-all" process, PC might be mediated postretinal site.

Language: Английский

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Chromatic Pupillometry Methods for Assessing Photoreceptor Health in Retinal and Optic Nerve Diseases

Frontiers in Neurology, Journal Year: 2019, Volume and Issue: 10

Published: Feb. 12, 2019

The pupillary light reflex is mediated by melanopsin-containing intrinsically-photosensitive retinal ganglion cells (ipRGCs), which also receive input from rods and cones. Melanopsin-dependent responses are short-wavelength sensitive, have a higher threshold of activation, much slower to activate de-activate compared with rod/cone-mediated responses. Given that rod/cone photoreceptors melanopsin differ in their response properties, stimuli can be designed stimulate preferentially each the different photoreceptor types, providing read-out function. This has given rise chromatic pupillometry methods aim assess health outer ipRGCs measuring blue or red stimuli. Here, we review types protocols been tested patients optic nerve disease, including approaches use short-duration exposures continuous exposure light. Across protocols, disease (e.g., retinitis pigmentosa Leber congenital amaurosis) show reduced absent dim blue-light used rod function, moderately-bright red-light cone By comparison, glaucoma ischemic neuropathy, but not mitochondrial disease) impaired during bright stimuli, post-illumination after offset, These proof-of-concept studies demonstrate damage ipRGCs. In future studies, it will important determine whether for screening early detection diseases. Such may prove useful objectively evaluating degree recovery ipRGC function blind who undergo gene therapy other treatments restore vision.

Language: Английский

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Attenuation of short wavelengths alters sleep and the ipRGC pupil response

Ophthalmic and Physiological Optics, Journal Year: 2017, Volume and Issue: 37(4), P. 440 - 450

Published: June 27, 2017

Abstract Purpose Exposure to increasing amounts of artificial light during the night may contribute high prevalence reported sleep dysfunction. Release hormone melatonin is mediated by intrinsically photosensitive retinal ganglion cells (ip RGC s). This study sought investigate whether level and quality can be modulated decreasing night‐time input ip s. Methods Subjects (ages 17–42, n = 21) wore short wavelength‐blocking glasses prior bedtime for 2 weeks. The ‐mediated post illumination pupil response was measured before after experimental period. Stimulation presented with a ganzfeld stimulator, including one‐second five‐seconds long wavelength light, imaged an infrared camera. Pupil diameter before, 60 s following stimulation, six‐second 30 area under curve offset were determined. actigraph device objective measurements activity, exposure, sleep. Saliva samples collected assess content. Pittsburgh Sleep Quality Index ( PSQI ) administered subjective quality. Results blue‐blocking 3:57 ± 1:03 h each night. After period, showed slower redilation phase, resulting in significantly increased decreased one five‐second when at same time day as baseline. Night from 16.1 7.5 pg mL −1 25.5 10.7 P < 0.01). Objectively duration 24 min, 408.7 44.9 431.5 42.9 min 0.001). Mean score improved 5.6 2.9 3.0 2.2. Conclusions use subjectively objectively levels duration, presumably result stimulation Alterations ‐driven suggest shift circadian phase. that minimising sunset help regulating patterns.

Language: Английский

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Crosstalk: The diversity of melanopsin ganglion cell types has begun to challenge the canonical divide between image‐forming and non‐image‐forming vision

The Journal of Comparative Neurology, Journal Year: 2020, Volume and Issue: 528(12), P. 2044 - 2067

Published: Jan. 31, 2020

Melanopsin ganglion cells have defied convention since their discovery almost 20 years ago. In the following, many types of these intrinsically photosensitive retinal (ipRGCs) emerged. mouse retina, there are currently six known (M1-M6) melanopsin cells, each with unique morphology, mosaics, connections, physiology, projections, and functions. While melanopsin-expressing usually associated behaviors like circadian photoentrainment pupillary light reflex, characterization multiple has demonstrated a reach that may extend far beyond non-image-forming vision. fact, studies shown individual potential to impact image-forming functions contrast sensitivity color opponency. Thus, goal this review is summarize morphological functional aspects in retina highlight respective roles Although cell do project brain targets, it important note only first step determining influence on Even so, visual system canonically been divided into two realms begun challenge boundary between them, providing an overlap information complementary rather than redundant. Further photoreceptors will no doubt continue illustrate ever-expanding role for

Language: Английский

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