purpose: there are a few researches regarding the effects of islamic fasting on visual system. the aim of this study was to investigate the effects of ramadan fasting on the amplitude of accommodation (aa), near point of convergence (npc), positive and negative fusional vergences (pfv and nfv, respectively) in visually healthy fasters. methods: aa, npc, pfv and nfv at far (6m) and near (40cm) w...

purpose : to evaluate the near visual performance of an accommodative intraocular lens (iol) tetraflex, in comparison to a standard monofocal foldable iol in cataract surgery. setting: eye research center , farabi eye hospital , department of ophthalmology, tehran university of medical sciences, iran . methods : forty six eyes of 23 patients with cataract underwent phacoemulsification and accom...

Ocular accommodation provides a well-focussed image, feedback for accurate eye movement control, and cues for depth perception. To accurately perform visually guided motor tasks, integration of ocular motor systems is essential. Children with motor coordination impairment are established to be at higher risk of accommodation anomalies. The aim of the present study was to examine the relationshi...

PURPOSE To estimate changes in surface shape and gradient refractive index (GRIN) profile in primate lenses as a function of accommodation. To quantify the contribution of surface shape and GRIN to spherical aberration changes with accommodation. METHODS Crystalline lenses from 15 cynomolgus monkeys were studied in vitro under different levels of accommodation produced by a stretching system....

PURPOSE We tested the hypothesis that changes in accommodation after instillation of Phenylephrine Hydrochloride (PHCl) observed in some studies could be caused by changes in optics. METHODS We performed two experiments to test the effects of PHCl on static and on dynamic accommodation in 8 and 6 subjects, respectively. Objective wavefront measurements were recorded of the static accommodatio...

OBJECTIVE Disparity cues can be a major drive to accommodation via the convergence accommodation to convergence (CA/C) linkage, but, on decompensation of exotropia, disparity cues are extinguished by suppression so this drive is lost. This study investigated accommodation and vergence responses to disparity, blur and proximal cues in a group of distance exotropes aged between 4 and 11 years bot...

Takashi Shibata Takashi Kawai Keiji Ohta Masaki Otsuki Nobuyuki Miyake Yoshihiro Yoshihara Tsuneto Iwasaki Abstract — This paper describes a method for reducing the discrepancy between accommodation and convergence when viewing stereoscopic 3-D images. The method uses a newly developed stereoscopic 3-D display system with a telecentric optical system and a mobile LCD. The examination of a mono-...

Sleep disturbances are an all-too-familiar symptom of jet lag and a prime source of complaints for transmeridian travelers and flight crews alike. They are the result of a temporary loss of synchrony between an abruptly shifted sleep period, timed in accordance with the new local day-night cycle, and a gradually reentraining circadian system. Scheduled exposure to bright light can, in principle...