Pupil dilation is known to quickly respond to changes in the brightness in the visual field and a person's cognitive workload while performing a visual task. Pupil dilation is rarely analyzed in usability studies although it can be measured by most video-based eye-tracking systems and yields highly relevant workload information. This is mainly due to two problems: First, the variety of factors ...

Previous research [11] refers to pupil size as a passive information channel that provides insight into the affective state of the viewer but defies any voluntary control. However, since physiological arousal is influenced by various cognitive processes, we assume that pupil behavior can be brought under control by strategies of emotional regulation and cognitive processing. In the present pape...

The pupillary responses to light in patients with depression and normal controls were evaluated among Chinese females. Four parameters related to the pupil were assessed using a video-based pupillometer. The results showed that there were significant differences in the pupil area in the darkness and the pupil area at the peak of constriction between depressed patients and normal controls.

The eyes of cuttlefish (Sepia officinalis) have a modified horizontal slit-pupil with a distinctive W-shape in bright light, while in darkness the pupil is circular. Two suggestions have previously been made for a function of the W-shape: (1) camouflaging the eye; (2) providing distance information. Since neither of these suggestions can fully explain the function of this pupil across the entir...

Rods, cones and melanopsin containing intrinsically photosensitive retinal ganglion cells (ipRGCs) operate in concert to regulate pupil diameter. The temporal properties of intrinsic ipRGC signalling are distinct to those of rods and cones, including longer latencies and sustained signalling after light offset. We examined whether the melanopsin mediated post-illumination pupil response (PIPR) ...

PURPOSE Pupil size is critical for optimal performance of presbyopic contact lenses. Although the effect of luminance is well known, little information is available regarding other contributing factors such as aging and refractive status. METHODS The cohort population comprised 304 patients (127 male, 177 female) aged 18 to 78 years. Pupils were photographed at three controlled luminance leve...

PURPOSE To assess through-focus polychromatic image sharpness of five US Food and Drug Administration-approved presbyopia-correcting intraocular lenses (IOLs) through a range of object vergences and pupil diameters utilizing an image sharpness algorithm. METHODS A 1951 US Air Force resolution target was imaged through a Crystalens AO (AO) (Bausch & Lomb Surgical, Aliso Viejo, California), Cry...

PURPOSE Glare problems originating from bright lights are generally experienced more strongly at night. The typical disability glare is known to result from retinal straylight. In this study, the effects of pupil diameter and, especially in the case of small pupils, of eye wall translucency on the amount of retinal straylight were investigated. METHODS Straylight was measured as a function of...