The pupil controls the amount of light entering the eye. We have examined both the time course for the development of the light reflex and pupil diameter before and after this event in 50 neonates. The pupillary light reflex was absent in ali neonates of less than 30 weeks' gestational age, it graduafly developed from this age and by 35 weeks it was present in all. Several possible mechanisms t...

Cognitive operations can be detected by reduction of the pupillary light response. Neurophysiological pathways mediating this reduction have not been distinguished. We utilized selective blockade of pupillary sphincter or dilator muscles to isolate parasympathetic or sympathetic activity during cognition, without modifying central processes. Pupil diameter was measured during the light reaction...

Changes in the three-dimensional structures of the myoepithelium of the dilator pupillae (MDP) during mydriasis and miosis were investigated in the rat by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Following fixation, SEM specimens were treated with sodium hydroxide to expose the muscle surface. Significant morphological differences were noted in the anterior...

Purpose. To show whether pregnancy affects the measurements of pupillary diameter and wavefront (WF) aberrations. Methods. This was a case-control study including 34 healthy pregnant women in the third trimester and age-matched 34 nonpregnant women. Only women who had no ocular abnormalities and no refractive error were included. We measured photopic and mesopic pupil diameter and WF aberration...

We utilized pupillary responses as an online measure of attentional allocation and fluctuations in attention in order to better examine both how attention is allocated to items in working memory (WM) and individual differences therein. We found that the pupillary response during a delay was modulated by the number of items to be held in memory, reaching asymptote close to capacity limits. Furth...

Eye response to light exposure is usually described through the pupillary light reflex, which controls the pupil diameter and allows for testing the sensory and motor functions of the eye. We have arranged an experimental setup and developed a procedure in order to improve the video-oculography experiment through high-speed imaging. The technique has been applied over eleven people distinguishi...

A 6-year girl of Indian ethnicity was referred for poor vision. Examination showed bilateral persistent pupillary membrane covering the central pupil. When pupil was dilated, iris strands were connecting the central 1.5 mm diameter circular membrane with the pupillary margins (Figure 1). Homatropine 2% eye drops, 12-hourly, and spectacle correction of astigmatism failed to improve acuities bett...

Results obtained in collaboration with B. Dreher are summarized. Ocular fixation was the indicator of the orienting response, and pupillary dilatation and ECoG arousal to olfactory stimuli were the indicators of the arousal response. To make precise recording possible, animals with pretrigeminal brain stem transection were used. After ablation of the anterior sigmoid gyrus or proreal gyrus the ...

This paper proposes a noninvasive method for estimating autonomic nervous activity from changes in dynamic parameters of a pupillary flash response. Our method is derived based on an analysis that clarifies the relationship between the autonomic nervous activity and the dynamic parameters using the human pupillary muscle plant model developed in our previous study. Moreover, we show that pupill...

PURPOSE To report a case of bilateral glaucoma related to pseudophacomorphic mechanism in one eye and pupillary block in the other eye after Visian Implantable Collamer Lens (ICL, STAAR Surgical) insertion. METHODS A 44 year-old female with high myopia underwent bilateral ICL implantation of MICL12.6 after sulcus diameter measurements were performed by Pentacam. RESULTS Pseudophacomorphic g...