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https://www.readbyqxmd.com/read/28079738/vision-problems-and-reduced-reading-outcomes-in-queensland-schoolchildren
#1
Shelley Hopkins, Geoff P Sampson, Peter L Hendicott, Joanne M Wood
PURPOSE: To assess the relationship between vision and reading outcomes in Indigenous and non-Indigenous schoolchildren to determine whether vision problems are associated with lower reading outcomes in these populations. METHODS: Vision testing and reading assessments were performed on 508 Indigenous and non-Indigenous schoolchildren in Queensland, Australia divided into two age groups: Grades 1 and 2 (6-7 years of age) and Grades 6 and 7 (12-13 years of age). Vision parameters measured included cycloplegic refraction, near point of convergence, heterophoria, fusional vergence range, rapid automatized naming, and visual motor integration...
January 12, 2017: Optometry and Vision Science: Official Publication of the American Academy of Optometry
https://www.readbyqxmd.com/read/28071728/determining-the-relative-contribution-of-retinal-disparity-and-blur-cues-to-ocular-accommodation-in-down-syndrome
#2
Lesley Doyle, Kathryn J Saunders, Julie-Anne Little
Individuals with Down syndrome (DS) often exhibit hypoaccommodation alongside accurate vergence. This study investigates the sensitivity of the two systems to retinal disparity and blur cues, establishing the relationship between the two in terms of accommodative-convergence to accommodation (AC/A) and convergence-accommodation to convergence (CA/C) ratios. An objective photorefraction system measured accommodation and vergence under binocular conditions and when retinal disparity and blur cues were removed...
January 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28031397/electrical-stimulation-of-superior-colliculus-affects-strabismus-angle-in-monkey-models-for-strabismus
#3
Suraj Upadhyaya, Hui Meng, Vallabh E Das
Disruption of binocular vision during the critical period for development leads to eye misalignment in humans and in monkey models. We have previously suggested that disruption within a vergence circuit could be the neural basis for strabismus. Electrical stimulation in the rostral superior colliculus (rSC) leads to vergence eye movements in normal monkeys. Therefore the purpose of this study was to investigate the effect of SC stimulation on eye misalignment in strabismic monkeys. Electrical stimulation was delivered to 51 sites in the intermediate and deep layers of the SC (400Hz, 0...
December 28, 2016: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28002561/compensation-of-presbyopia-with-the-light-sword-lens
#4
Alejandro Mira-Agudelo, Walter Torres-Sepúlveda, John F Barrera, Rodrigo Henao, Narcyz Blocki, Krzysztof Petelczyc, Andrzej Kolodziejczyk
Purpose: We present the first physiological evaluation of the use of the light sword lens (LSL) for presbyopia compensation. The LSL is an axially asymmetric optical element designed for imaging with extended depth of focus. Methods: A monocular visual simulator setup is implemented to measure visual acuity (VA). Physiological presbyopia is "mimicked" in human subjects by paralysis of the ciliary muscle, using topical application of a muscarinic antagonist. The effect of a contact lens-configured LSL on the mimicked presbyopia visual system is evaluated by measuring VA as a function of target vergence...
December 1, 2016: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/27994843/the-role-of-vertical-disparity-in-distance-and-depth-perception-as-revealed-by-different-stereo-camera-configurations
#5
Cyril Vienne, Justin Plantier, Pascaline Neveu, Anne-Emmanuelle Priot
Vertical binocular disparity is a source of distance information allowing the portrayal of the layout and 3D metrics of the visual space. The role of vertical disparity in the perception of depth, size, curvature, or slant of surfaces was revealed in several previous studies using cue conflict paradigms. In this study, we varied the configuration of stereo-cameras to investigate how changes in the horizontal and vertical disparity fields, conflicting with the vergence cue, affect perceived distance and depth...
November 2016: I-Perception
https://www.readbyqxmd.com/read/27973591/attentional-selection-accompanied-by-eye-vergence-as-revealed-by-event-related-brain-potentials
#6
Maria Sole Puig, Josep Marco Pallarés, Laura Perez Zapata, Laura Puigcerver, Josep Cañete, Hans Supèr
Neural mechanisms of attention allow selective sensory information processing. Top-down deployment of visual-spatial attention is conveyed by cortical feedback connections from frontal regions to lower sensory areas modulating late stimulus responses. A recent study reported the occurrence of small eye vergence during orienting top-down attention. Here we assessed a possible link between vergence and attention by comparing visual event related potentials (vERPs) to a cue stimulus that induced attention to shift towards the target location to the vERPs to a no-cue stimulus that did not trigger orienting attention...
2016: PloS One
https://www.readbyqxmd.com/read/27928407/vergence-neural-pathways-a-systematic-narrative-literature-review
#7
REVIEW
Annabelle Searle, Fiona J Rowe
Research in the neural pathway for vergence is less understood in comparison to the other four visual eye movements. The aim of this study was to review the literature on vergence neural pathways and associated disorders. A review of previous published literature though to March 2016 was conducted. Intracranial pathologies that affect entire neural functioning were found to cause convergence insufficiencies. In contrast, pathologies with a more localised intracranial lesion cause more specific vergence disorders...
October 2016: Neuro-ophthalmology
https://www.readbyqxmd.com/read/27921322/the-heterophoria-of-3-5-year-old-children-as-a-function-of-viewing-distance-and-target-type
#8
Mary E Troyer, Vidhyapriya Sreenivasan, T J Peper, T Rowan Candy
PURPOSE: Heterophoria is the misalignment of the eyes in monocular viewing and represents the accuracy of vergence driven by all classical cues except disparity. It is challenging to assess restless children using clinical cover tests, and phoria in early childhood is poorly understood. Here we used eye tracking to assess phoria as a function of viewing distance and target in adults and young children, with comparison to clinical cover tests. METHODS: Purkinje image tracking (MCS PowerRefractor) was used to record eye alignment in adults (19-28 years, N = 24) and typically developing children (3-5 years, N = 24)...
January 2017: Ophthalmic & Physiological Optics: the Journal of the British College of Ophthalmic Opticians (Optometrists)
https://www.readbyqxmd.com/read/27876513/are-high-lags-of-accommodation-in-myopic-children-due-to-motor-deficits
#9
Vivek Labhishetty, William R Bobier
Children with a progressing myopia exhibit an abnormal pattern of high accommodative lags coupled with high accommodative convergence (AC/A) and high accommodative adaptation. This is not predicted by the current models of accommodation and vergence. Reduced accommodative plant gain and reduced sensitivity to blur have been suggested as potential causes for this abnormal behavior. These etiologies were tested by altering parameters (sensory, controller and plant gains) in the Simulink model of accommodation...
January 2017: Vision Research
https://www.readbyqxmd.com/read/27873014/binocular-function-changes-produced-in-response-to-overnight-orthokeratology
#10
Gema Felipe-Marquez, María Nombela-Palomo, Catalina Palomo-Álvarez, Isabel Cacho, Amelia Nieto-Bona
PURPOSE: To analyze the binocular function changes produced on subjects undergoing overnight orthokeratology (OK) treatment over short-term (3 months) and long-term (3 years) wear. METHODS: A prospective, longitudinal study on young adult subjects with low to moderate myopia was carried out. Binocular function was assessed by the following sequence of tests: Distance and near horizontal phoria (Von Graefe technique), distance and near horizontal vergence ranges (Risley rotary prisms), accommodative convergence/accommodation (AC/A) ratio (gradient method) and the near point of convergence (standard push-up technique)...
January 2017: Graefe's Archive for Clinical and Experimental Ophthalmology
https://www.readbyqxmd.com/read/27867718/temporal-multiplexing-with-adaptive-optics-for-simultaneous-vision
#11
Eleni Papadatou, Antonio J Del Águila-Carrasco, Iván Marín-Franch, Norberto López-Gil
We present and test a methodology for generating simultaneous vision with a deformable mirror that changed shape at 50 Hz between two vergences: 0 D (far vision) and -2.5 D (near vision). Different bifocal designs, including toric and combinations of spherical aberration, were simulated and assessed objectively. We found that typical corneal aberrations of a 60-year-old subject changes the shape of objective through-focus curves of a perfect bifocal lens. This methodology can be used to investigate subjective visual performance for different multifocal contact or intraocular lens designs...
October 1, 2016: Biomedical Optics Express
https://www.readbyqxmd.com/read/27859646/prevalence-of-non-strabismic-anomalies-of-binocular-vision-in-tamil-nadu-report-2-of-band-study
#12
Jameel Rizwana Hussaindeen, Archayeeta Rakshit, Neeraj Kumar Singh, Ronnie George, Meenakshi Swaminathan, Suman Kapur, Mitchell Scheiman, Krishna Kumar Ramani
BACKGROUND: Population-based studies on the prevalence of non-strabismic anomalies of binocular vision in ethnic Indians are more than two decades old. Based on indigenous normative data, the BAND (Binocular Vision Anomalies and Normative Data) study aims to report the prevalence of non-strabismic anomalies of binocular vision among school children in rural and urban Tamil Nadu. METHODS: This population-based, cross-sectional study was designed to estimate the prevalence of non-strabismic anomalies of binocular vision in the rural and urban population of Tamil Nadu...
November 18, 2016: Clinical & Experimental Optometry: Journal of the Australian Optometrical Association
https://www.readbyqxmd.com/read/27832268/an-active-efficient-coding-model-of-optokinetic-nystagmus
#13
Chong Zhang, Jochen Triesch, Bertram E Shi
Optokinetic nystagmus (OKN) is an involuntary eye movement responsible for stabilizing retinal images in the presence of relative motion between an observer and the environment. Fully understanding the development of OKN requires a neurally plausible computational model that accounts for the neural development and the behavior. To date, work in this area has been limited. We propose a neurally plausible framework for the joint development of disparity and motion tuning in the visual cortex and of optokinetic and vergence eye-movement behavior...
November 1, 2016: Journal of Vision
https://www.readbyqxmd.com/read/27812325/benefits-from-vergence-rehabilitation-evidence-for-improvement-of-reading-saccades-and-fixations
#14
François Daniel, Aurélien Morize, Dominique Brémond-Gignac, Zoï Kapoula
We hypothesize that binocular coordination of saccades is based on continuous neuroplasticity involving interactions of saccades and vergence. To test this hypothesis we study reading saccades in young students who were diagnosed for vergence disorders before and after vergence rehabilitation. Following orthoptic evaluation and symptomatology screening, 5 weekly sessions of vergence rehabilitation were applied with the REMOBI vergence double step protocole (see Kapoula et al., 2016). Using the Eyeseecam videoculography device we measured vergence as well as saccades and fixations during a reading test four times: at the beginning and at the end of the first and of the fifth vergence rehabilitation session...
2016: Frontiers in Integrative Neuroscience
https://www.readbyqxmd.com/read/27802556/effect-of-osteopathic-cranial-manipulative-medicine-on-visual-function
#15
Mark E Sandhouse, Diana Shechtman, Gregory Fecho, Elena M Timoshkin
CONTEXT: The effects of osteopathic cranial manipulative medicine (OCMM) on visual function have been poorly characterized in the literature. Based on a pilot study conducted by their research group, the authors conducted a study that examined whether OCMM produced a measurable change in visual function in adults with cranial asymmetry. STUDY DESIGN: Randomized, controlled, double-blinded clinical trial. The intervention and control (sham therapy) were applied during 8 weekly visits, and participants in both groups received 8 weekly follow-up visits...
November 1, 2016: Journal of the American Osteopathic Association
https://www.readbyqxmd.com/read/27796049/binocular-vision-anomalies-and-normative-data-band-in-tamil-nadu-report-1
#16
Jameel Rizwana Hussaindeen, Archayeeta Rakshit, Neeraj Kumar Singh, Meenakshi Swaminathan, Ronnie George, Suman Kapur, Mitchell Scheiman, Krishna Kumar Ramani
BACKGROUND: This population-based, cross-sectional study was designed to determine normative data for binocular vision and accommodative testing in rural and urban populations of Tamil Nadu. METHODS: A sample of 936 was determined, based on a previous pilot study. The epidemiological field work included a comprehensive eye examination and a binocular vision and accommodative assessment carried out in a total of four public schools, two each in the rural and urban arms of Chennai...
October 30, 2016: Clinical & Experimental Optometry: Journal of the Australian Optometrical Association
https://www.readbyqxmd.com/read/27789230/allocentric-information-is-used-for-memory-guided-reaching-in-depth-a-virtual-reality-study
#17
Mathias Klinghammer, Immo Schütz, Gunnar Blohm, Katja Fiehler
Previous research has demonstrated that humans use allocentric information when reaching to remembered visual targets, but most of the studies are limited to 2D space. Here, we study allocentric coding of memorized reach targets in 3D virtual reality. In particular, we investigated the use of allocentric information for memory-guided reaching in depth and the role of binocular and monocular (object size) depth cues for coding object locations in 3D space. To this end, we presented a scene with objects on a table which were located at different distances from the observer and served as reach targets or allocentric cues...
December 2016: Vision Research
https://www.readbyqxmd.com/read/27776082/effect-of-decentration-on-the-optical-quality-of-two-intraocular-lenses
#18
Carolina Ortiz, José J Esteve-Taboada, Lurdes Belda-Salmerón, Daniel Monsálvez-Romín, Alberto Domínguez-Vicent
PURPOSE: To analyze the effect of decentration on the optical quality of two diffractive-refractive intraocular lenses, a bifocal and a trifocal, when displaced laterally (horizontal direction) from the center. METHODS: The AT LISA 809M IOL (+3.75 D add) with two main foci and the AT LISA tri 839MP intraocular lens with three main foci (Carl Zeiss Meditec AG, Jena, Germany) were analyzed. The optical quality of the intraocular lenses was measured with the PMTF (power and modulation transfer function [MTF] measurement for refractive and diffractive intraocular lenses) optical bench (Lambda-X, Nivelles, Belgium)...
December 2016: Optometry and Vision Science: Official Publication of the American Academy of Optometry
https://www.readbyqxmd.com/read/27756701/tonic-accommodation-predicts-closed-loop-accommodation-responses
#19
Chunming Liu, Stefanie A Drew, Eric Borsting, Amy Escobar, Lawrence Stark, Christopher Chase
The purpose of this study is to examine the potential relationship between tonic accommodation (TA), near work induced TA-adaptation and the steady state closed-loop accommodation response (AR). Forty-two graduate students participated in the study. Various aspects of their accommodation system were objectively measured using an open-field infrared auto-refractor (Grand Seiko WAM-5500). Tonic accommodation was assessed in a completely dark environment. The association between TA and closed-loop AR was assessed using linear regression correlations and t-test comparisons...
December 2016: Vision Research
https://www.readbyqxmd.com/read/27668492/holographic-refraction-and-the-measurement-of-spherical-ametropia
#20
Nicholas Hoai Nam Nguyen
PURPOSE: To evaluate the performance of a holographic logMAR chart for the subjective spherical refraction of the human eye. METHODS: Bland-Altman analysis was used to assess the level of agreement between subjective spherical refraction using the holographic logMAR chart and conventional autorefraction and subjective spherical refraction. RESULTS: The 95% limits of agreement (LoA) were calculated between holographic refraction and the two standard methods (subjective and autorefraction)...
October 2016: Optometry and Vision Science: Official Publication of the American Academy of Optometry
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