The use of pupil-plane filters in microscopes has been proposed as a method of producing superresolution. Here it is shown that pupil-plane filters cannot increase the support of the transfer function for a large class of optical systems, implying that resolution cannot be improved solely by adding pupil-plane filters to an instrument. However, pupil filters can improve signal-to-noise performa...

Rapid and stable control of pupil size in response to light is critical for vision, but the neural coding mechanisms remain unclear. Here, we investigated the neural basis of pupil control by monitoring pupil size across time while manipulating each photoreceptor input or neurotransmitter output of intrinsically photosensitive retinal ganglion cells (ipRGCs), a critical relay in the control of ...

Real-time, accurate, and robust pupil detection is an essential prerequisite for pervasive video-based eye-tracking. However, automated pupil detection in real-world scenarios has proven to be an intricate challenge due to fast illumination changes, pupil occlusion, non centered and off-axis eye recording, and physiological eye characteristics. In this paper, we propose and evaluate a method ba...

Cognitive demands in response conflict paradigms trigger negative affect and avoidance behavior. However, not all response conflict studies show increases in physiological indices of emotional arousal, such as pupil diameter. In contrast to earlier null-results, this study shows for the first time that small (about 0.02 mm) conflict-related pupil dilation can be observed in a Simon task when st...

The aim of this study was to investigate the analgesic effects of hypnotic pain control on experimental pain by measuring pupil reactions as an objective psycho-physiologic parameter. Twenty-two healthy volunteers (11 female and 11 male) aged between 22 and 35 years participated in the study. Pupil diameter was measured as baseline measurement (i.e., static measurement) in the non-hypnotic and ...

Pupil size is collectively controlled by the sympathetic dilator and parasympathetic sphincter muscles. Locus coeruleus (LC) activation has been shown to evoke pupil dilation, but how the sympathetic and parasympathetic pathways contribute to this dilation remains unknown. We examined pupil dilation elicited by LC activation in lightly anesthetized rats. Unilateral LC activation evoked bilatera...

PURPOSE To compare pupil sizes measured with the Colvard pupillometer, Procyon pupillometer, and NIDEK OPD-Scan. METHODS Pupil diameter was measured in 90 consecutive eyes from 55 patients under mesopic and scotopic light conditions with all three instruments. RESULTS The mean scotopic pupil diameter was 6.3+/-0.98 mm with the Colvard pupillometer and 6.45+/-1.01 mm with the Procyon pupillo...

Melanopsin containing intrinsically photosensitive Retinal Ganglion cells (ipRGCs) mediate the pupil light reflex (PLR) during light onset and at light offset (the post-illumination pupil response, PIPR). Recent evidence shows that the PLR and PIPR can provide non-invasive, objective markers of age-related retinal and optic nerve disease; however there is no consensus on the effects of healthy ...

Pupil dilation is classically associated with increase in cognitive load in humans. Here, we studied the potential link between human pupil dilation and meaning integration effort as indexed by event-related brain potentials (ERPs). We recorded pupil size variation and ERPs simultaneously while participants were presented with matching or unrelated picture-word pairs. Whilst relatedness in mean...