An eye with angle closure glaucoma is anatomically characterized by a short axial length, a shallow anterior chamber, a thickened lens that is situated relatively anteriorly and a small corneal diameter. These conditions may lead to the development of relative pupillary block. Pupillary block is classically managed with a peripheral iridectomy which provides a route for the aqueous to drain. Bu...

INTRODUCTION The purpose of this study was to develop and initially validate an objective, yet quick, method for assessment of human fatigue. This aim can be achieved by the use of an optical, non-contact method of analysis of pupil activity. The study involved 2 phenomena typical for the behavior of the human pupil: pupillary reflex and pupillary movements. The 1st phenomenon is related to the...

Pupillary dilatation has recently been reported as a physiological measure of degree of attention paid to environmental stimuli (Hess & Polt, 1960, 1964). Hess and Polt's research has operationally defined one variable and has provided data that allows researchers to speculate about several others. This variable is interest-disinterest. The purpose of the present investigation was to examine th...

Clinically, meditative practices have become increasingly relevant, decreasing anxiety in patients and increasing antibody production. However, few studies have examined the physiological correlates, or effects of the incorporation of meditative practices. Because pupillary reactivity is a marker for autonomic changes and emotional processing, we hypothesized that the pupillary responses of min...

In ophthalmology, a pupillometer, a device to measure the diameter of the pupil of the eye, can provide information on the function of the autonomic nervous system. The current pupillometers on the market are either too large to be a handheld instrument, or relatively expensive. In this study, a pupillometer based on a smartphone was designed. Both white and infrared LEDs and a 3M pixel camera ...

The recent discovery of melanopsin-containing retinal ganglion cells (mRGCs) has led to a fundamental reassessment of non-image forming processing, such as circadian photoentrainment and the pupillary light reflex. In the conventional view of retinal physiology, rods and cones were assumed to be the only photoreceptors in the eye and were, therefore, considered responsible for non-image process...

PURPOSE To determine whether there is alpha 1-adrenergic receptor heterogeneity associated with the regulation of intraocular pressure (IOP) and mydriasis in rabbits, the authors tested the hypothesis by characterizing the ability of the selective alpha 1-adrenergic antagonist, bunazosin, to block the ocular hypertensive and mydriatic responses to alpha 1-adrenoceptor stimulation by either nore...

PURPOSE. To report and present data on a method for monitoring patient vigilance during a visual field test by using pupillometry. METHODS. Pupil diameter was recorded at 60 Hz with an eye movement tracking system in 13 patients attending the glaucoma outpatient clinics at Manchester Royal Eye Hospital. The patients were instructed to fixate a central target and to press a response button when ...

The contributions of separate sympathetic and parasympathetic pathways to pupillary dilation during a sustained processing task were studied through environmental and pharmacological manipulations. In Experiment 1, 22 healthy volunteers (11 female) performed a serial Subtract 7 task while pupil diameter was recorded both during moderate room light and in darkness. In a control for verbalization...

RATIONALE It has been shown previously that the amplitude of the pupillary light reflex response decreases when subjects anticipate an aversive stimulus (i.e. electric shock), compared to periods when subjects are resting ('fear-inhibited light reflex'). OBJECTIVE To compare the effects of the anticipation of an electric shock (putative aversive event) and of an acoustic stimulus (putative ne...