In great cormorants (Phalacrocorax carbo sinensis), corneal refractive powers, determined by photokeratometry, ranged between 52.1 diopters (52.1 D) and 63.2 D. Photorefractive reflexes, determined by infrared video photorefraction, indicated that in voluntary dives the cormorants accommodate within 40-80 ms of submergence and with myopic focusing relative to the photorefractor attained when pr...

We investigated the roles that blur, proximity and vergence cues play in the development of accommodation. Accommodative responses to targets incorporating one or more of these cues were measured for four adults and eight infants at 1.5 and 3 months of age using eccentric photorefraction. Adults showed accurate accommodation to blur cues, and variable accommodation with proximity cues alone. So...

The recent advances in the photorefraction of doped lithium niobate crystals are reviewed. Materials have always been the main obstacle for commercial applications of photorefractive holographic storage. Though iron-doped LiNbO3 is the mainstay of holographic data storage efforts, several shortcomings, especially the low response speed, impede it from becoming a commercial recording medium. Thi...

PURPOSE To compare the accuracy of noncycloplegic photorefraction (NCP) with that of cycloplegic refraction (CR) for detecting refractive amblyopia risk factors (RARFs) and to determine cutoff points. METHODS In this diagnostic test study, right eyes of 185 children (aged 1 to 14 years) first underwent NCP using the PlusoptiX SO4 photoscreener followed by CR. Based on CR results, hyperopia (≥...

The possibility of volumetric phase recording based on photo-oxidation the side anthracene groups a new polymer with glass transition temperature ~338 K by oxygen that enters layer across boundary atmospheric medium, was established experimentally. Volumetric holographic gratings maximum diffraction efficiency 2.5–9.5% were recorded radiation from He–Ne laser (λ = 633 nm) in layers 5–20-μm thic...

PURPOSE Prior studies in humans measured time constants of biometric accommodative changes as a function of amplitude, and prior studies in monkeys used slit lamp videography to analyze dynamic lenticular accommodative movements. Neither of these studies related biometric changes to refractive changes. We wished to develop and test methodology to begin to test the hypothesis that ocular biometr...