PURPOSE To evaluate a new disposable, small-pupil expansion device in tamsulosin patients with intraoperative floppy-iris syndrome (IFIS) having cataract surgery. SETTING Private practice, Los Altos, California, USA. METHODS The 5-0 polypropylene Malyugin pupil expansion device (MicroSurgical Technology) was used in 30 eyes from 21 tamsulosin patients having routine cataract surgery. The pu...

PURPOSE (1) To use finite element (FE) modelling to estimate local iris stresses (i.e. internal forces) as a result of mechanical pupil expansion; and to (2) compare such stresses as generated from several commercially available expanders (Iris hooks, APX dilator and Malyugin ring) to determine which design and deployment method are most likely to cause iris damage. METHODS We used a biofidel...

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...