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 ...

PURPOSE To evaluate the feasibility of screening for retinopathy of prematurity (ROP) by assessing the pupillary response to mydriatics. METHODS This observational case series included 134 eyes of 67 premature infants with birth weight less than 2,000 grams and gestational age less than 33 weeks. A composite eye drop composed of phenylephrine 1%, tetracaine and tropicamide 0.5% was applied 3 ...

PURPOSE This study aimed to quantify the pupillary light reaction during high altitude exposure using the state of the art Compact Integrated Pupillograph (CIP) and to investigate a potential correlation of altered pupil reaction with severity of acute mountain sickness (AMS). This work is related to the Tübingen High Altitude Ophthalmology (THAO) study. METHODS Parameters of pupil dynamics (...

The modulation transfer function (MTF) of human eyes for different pupil sizes was measured in a group of normal young subjects by use of a double-pass method. Measurements were carried out in the fovea, with monochromatic red light, paralyzed accommodation, artificial pupils, and optimum spherical refraction in each subject. For each pupil size both the averaged MTF and the intersubject variab...

Objective: To investigate the additive influence of peripheral stimuli, we examined accommodative and pupillary response for a fixation target with peripheral stimuli of different luminance at various distances. Methods: The refractive error and size of pupil diameter were measured monocularly by an autorefkeratometer, looking at a central target of 1 degree of arc at a distance of 100 cm throu...

OBJECTIVE To explore working memory and the ability to process different emotional stimuli in patients with first-onset and untreated minor (mild or moderate) depression. METHODS Patients with first-onset and previously untreated minor depression, and healthy controls, were enrolled. Using a modified Sternberg working memory paradigm to investigate the combined effects of emotional stimuli wi...

Some of the different currently applied approaches that correct presbyopia may reduce stereovision. In this work, stereo-acuity was measured for two methods: (1) monovision and (2) small aperture inlay in one eye. When performing the experiment, a prototype of a binocular adaptive optics vision analyzer was employed. The system allowed simultaneous measurement and manipulation of the optics in ...

We compared 7 methods of measuring visual fatigue--accommodation power, visual acuity, pupil diameter, critical fusion frequency (CFF), eye movement velocity, subjective rating of visual fatigue, and task performance--for their sensitivity to visual load. In the experiment, 10 participants performed a monitoring task at 2 viewing distances, read articles under 2 levels of screen contrast, and t...

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...

Ocular changes (prostaglandin E, protein, pupil diameter, and intraocular pressure) induced by photodisruption of pigmented rabbit iris with neodymium-yttrium aluminum garnet (Nd-YAG) laser and the effect of topical indomethacin upon those changes were examined. Concentrations of prostaglandin E in laser-treated eyes (1,3,5,10, and 20 lesions) were substantially greater than those in normal eye...