Effects of photopic and cirtopic illumination on steady state pupil sizes

Rao, Feng; Chan, Alan H. S.

doi:10.1016/j.visres.2017.02.010

Cited by 18 publications

(17 citation statements)

References 12 publications

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“…Our study has shown that the pupil's adaptation process cannot be described without a temporal parameter, especially when it comes to different distributed spectra compositions. A further model approach by Rao et al used a melatonin action factor for ipRGC weighting to take the spectral influence for the tonic pupil diameter into account 97 . However, his model is based exclusively on phosphor-converted white LED light sources, which may reduce the generality of the spectral dependence.…”

Section: Discussionmentioning

confidence: 99%

Prediction accuracy of L- and M-cone based human pupil light models

Zandi

Klabes

Khanh

2020

Sci Rep

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Multi-channel LED luminaires offer a powerful tool to vary retinal receptor signals while keeping visual parameters such as color or brightness perception constant. This technology could provide new fields of application in indoor lighting since the spectrum can be enhanced individually to the users' favor or task. One possible application would be to optimize a light spectrum by using the pupil diameter as a parameter to increase the visual acuity. A spectral-and time-dependent pupil model is the key requirement for this aim. We benchmarked in our work selected Land M-cone based pupil models to find the estimation error in predicting the pupil diameter for chromatic and polychromatic spectra at 100 cd/m 2. We report an increased estimation error up to 1.21 mm for 450 nm at 60-300 s exposure time. At short exposure times, the pupil diameter was approximately independent of the used spectrum, allowing to use the luminance for a pupil model. Polychromatic spectra along the Planckian locus showed at 60-300 s exposure time, a prediction error within a tolerance range of ± 0.5 mm. The time dependency seems to be more essential than the spectral dependency when using polychromatic spectra. The pupil aperture is an essential factor in photometric and visual investigations because of its direct influence on both retinal illumination and the retinal image quality 1. A smaller pupil diameter can ensure a larger depth of field 2 and achieve a decrease of optical aberrations 3,4 , which has positive effects on the visual acuity of the eye 4,5. Visual acuity is relevant in the interior lighting of workplaces or production facilities since an enhanced visual performance leads to fewer accidents or human injuries 6. Various studies have shown that the optimal pupil diameter is approximately between two and three millimeters for visual tasks in the photopic luminance range 1,4,7-11. With today's technology of multi-channel LED luminaires, it is possible to optimize artificial light spectra to influence the pupil aperture, color perception, brightness perception or other lighting metrics 12,13. The number of narrow-band light-emitting diodes in such a system determines the degree of freedom, which allows keeping specific parameters constant while changing others. The first step to actively optimize the pupil aperture through illumination without influencing other image-forming vision parameters such as brightness or color perception is the construction of an accurate model which predicts the spectral and time-dependent pupil diameter. Such a model can be used in a heuristic or gradient-based optimization procedure as an objective or constraint function to design the desired light spectrum for visual tasks. Eight empirical models are proposed in the literature with different dependent parameters and test conditions. The most famous models are from Holladay 14 , Crawford 15 , Moon and Spencer 16 , De Groot and Gebhard 17 , Stanley and Davies 18 , Barten 19 and Blackie and Howland 20. In 2012, Watson and Yellot 21 reviewed these pup...

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Section: Discussionmentioning

confidence: 99%

Prediction accuracy of L- and M-cone based human pupil light models

Zandi

Klabes

Khanh

2020

Sci Rep

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“…A recent study reported an attempt to derive a formula for predicting pupil size from melanopsin activation but only focused on a rather narrow luminance range (50–300 cd/m 2 ; Rao, Chan, & Zhu, 2017). While this is a good start, it might be a useful empirical exercise to collect natural pupil sizes under a large range of illumination conditions (indoors, outdoors) under natural behavior with conjoint spectral measurements.…”

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confidence: 99%

Photoreceptor inputs to pupil control

Spitschan

2019

Journal of Vision

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

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“…The particular influence of the excitation of each photoreceptor on pupillary size has not yet been separated in humans so as to identify their independent and combined contributions 68 . Some authors find that the cones and ipRGCs influence the pupillary size together 69 . Other authors suggest that the selective activation of the cones ρ , γ , and β does not necessarily produce the same effect (constriction or dilation) on pupillary size 11,70 .…”

Section: Results and Disscusionmentioning

confidence: 99%

“…68 Some authors find that the cones and ipRGCs influence the pupillary size together. 69 Other authors suggest that the selective activation of the cones ρ, γ, and β does not necessarily produce the same effect (constriction or dilation) on pupillary size. 11,70 This topic is currently the subject of extensive and active research work in the scientific community.…”

Section: Pupillary Diameter and Photoreceptors Excitationsmentioning

confidence: 99%

Relationship between pupillary size, brightness, and photoreceptor responses for unrelated self‐luminous stimuli at low photopic light levels

Salinas¹,

Hermans

Sandoval³

et al. 2020

Color Research & Application

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Research on the correlation between the initial pupillary light reflex, the perceptual brightness, and the excitations of the photoreceptors was performed for unrelated self-luminous 10 stimuli at low photopic light levels (5 to 80 cd/ m 2). All stimuli were optically characterized using a spectroradiometer. For determining the pupillary diameter, an Eye Tracker was used. The perceived brightness was evaluated with the magnitude estimation method. Test stimuli were presented alternating with a reference stimulus and the Michelson contrast of the pupillary diameter between test and reference conditions was calculated. Six observers (three female and three male) participated, with ages between 30 and 39 years (with an average of 34.5 years). It was found that the coefficient of determination between the pupillary response and the perceived stimulus brightness was higher than the corresponding value for luminance, allowing the suggestion that brightness has a greater effect on pupillary size than luminance. Nevertheless, this is not the complete story: highly saturated red and blue stimuli both induce a high brightness perception but the pupil contraction induced by the blue stimuli is much greater than for the red stimuli. Pupillary diameter was also studied as a function of the relative excitations of the five photoreceptors. The effect of rod and ipRGC excitations on pupillary size variation seems to be larger than that of the other photoreceptors. However, for the working conditions prevailing in this research, it could be expected that rods are not very active and that the ipRGC response might be the major driving mechanism.

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Effects of photopic and cirtopic illumination on steady state pupil sizes

Cited by 18 publications

References 12 publications

Prediction accuracy of L- and M-cone based human pupil light models

Prediction accuracy of L- and M-cone based human pupil light models

Photoreceptor inputs to pupil control

Relationship between pupillary size, brightness, and photoreceptor responses for unrelated self‐luminous stimuli at low photopic light levels

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