THE SURHUSING possibility that the widening of the human pupil in the dark accurately reflects regeneration of rhodopsin in the retinal rods was first suggested by the experiments of ALPERN and CAMPBELL (1962a). They found that recovery of the pupil size in the dark after a full rhodopsin bleach was very slow. After an initial transient widening and narrowing in the first minute, the pupil retu...

A significant body of literature supports the contention that pupil size varies depending on cognitive load, affective state, and level of drowsiness. Here we assessed whether oculometric measures such as gaze position, blink frequency and pupil size were correlated with the occurrence and time course of self-reported mind-wandering episodes. We recorded the pupil size of two subjects engaged i...

PURPOSE To study the effect of pupil size on the relationship between refractive astigmatism and uncorrected distance visual acuity (UDVA) and pseudoaccommodation in pseudophakic eyes. METHODS Thirty-six eyes from 36 patients who underwent phacoemulsification and intraocular lens (IOL) implantation were included. All eyes were divided into two groups based on the presence of postoperative-wit...

PURPOSE To compare postoperative changes in apparent photopic and mesopic pupil size and centration in relation to cornea reflection landmarks after cataract surgery. SETTING LaserVision.gr Clinical and Research Eye Institute, Athens, Greece. DESIGN Prospective consecutive case study. METHODS Pupils were imaged for pupil size and corneal vertex location before and 1-month after cataract s...

During recognition memory tests participants' pupils dilate more when they view old items compared to novel items. We sought to replicate this "pupil old/new effect" and to determine its relationship to participants' responses. We compared changes in pupil size during recognition when participants were given standard recognition memory instructions, instructions to feign amnesia, and instructio...

The scaling of root mean square (RMS) wave aberration in an isometrically growing eye is investigated, along with changes due to measurements made at different relative pupil sizes. It is found that, relative to an initial state, if an eye expands in all directions by the factor k, and the wave aberration is then measured at a relative pupil size which has changed over the pupil size used for t...

Pupil is controlled by the activity of the autonomous system. Under constant light and visual stimulus, it performs complex size oscillations and movements. Here, it is assumed that pupil behavior can be described by some unknown nonlinear deterministic rules. The techniques of time series embedding are applied to pupil size, obtaining a trajectory in the phase space. A trajectory is also obtai...

Many nonvisual functions are regulated by light through a photoreceptive system involving melanopsin-expressing retinal ganglion cells that are maximally sensitive to blue light. Several studies have suggested that the ability of light to modulate circadian entrainment and to induce acute effects on melatonin secretion, subjective alertness, and gene expression decreases during aging, particula...

175 words Text (excluding references and figure captions): 5526 References: 19 entries Figures: 9 Tables: 0 Abstract Pupil size is known to quickly adapt to changes in the luminance within the visual field and the observer’s cognitive workload while performing a visual task. Pupil size is rarely analyzed in eye-movement studies although it is measured by most video-based eyetracking systems. Th...

PURPOSE In this work, we investigated the pupillary conditions during straylight measurement, and the potential effect this might have on the measured straylight. METHODS Five young (26-29-years-old) and 15 older (50-68-years-old) individuals participated in this study. First, the pupil diameter of both eyes was measured at three room illuminances. Next, straylight was assessed at two room il...