Binocular vision

AIM: To determine age norms in the first three years of life for grating visual acuity and contrast sensitivity obtained with Lea grating test and Hiding Heidi low contrast face test. METHODS: Lea grating test was used to estimate binocular grating acuity and Hiding Heidi low contrast face test was used to estimate contrast sensitivity in 600 healthy infants and children. Age ranged from 3 to 36mo subdivided into 12 groups subjected for full ophthalmologic and pediatric examinations...

Purpose: The measurement of achromatic sensitivity has been an important tool for monitoring subtle changes in vision as the result of disease or response to therapy. In this study, we aimed to provide a normative data set for achromatic and chromatic contrast sensitivity functions within a common cone contrast space using an abbreviated measurement approach suitable for clinical practice. In addition, we aimed to provide comparisons of achromatic and chromatic binocular summation across spatial frequency...

Understanding which aspects of vision are related to falls is important. We examine the associations between tests of balance, mobility, fear of falling (FES-1) and aspects of vision in 72 adults aged 70+. Balance and mobility were examined using the One Legged Stance test (OLST), the Sit to Stand test (STST) and the 5 Meter Walking test (5MWT). Visual measures included visual acuity (VA), contrast sensitivity, stereoacuity, binocular vision (BV) measurements, Useful field of View (UFV) and Attended Field of View (AFOV)...

In social interactions, it is highly salient to us where other people are looking. The ability to recover this information is critical to typical social development, helping us to coordinate our attention and behavior with others and understand their intentions and mental states [1-3]. The depth and direction in which another individual is fixating are specified jointly by their head position, eye deviation, and binocular vergence [4, 5]. It is hereto unknown, however, whether this dynamic visual information about others' focus of attention affects how we ourselves see the world...

INTRODUCTION: Fixational saccades are miniature eye movements that constantly change the gaze during attempted visual fixation. Visually guided saccades and fixational saccades represent an oculomotor continuum and are produced by common neural machinery. Patients with strabismus have disconjugate binocular horizontal saccades. We examined the stability and variability of eye position during fixation in patients with strabismus and correlated the severity of fixational instability with strabismus angle and binocular vision...

Purpose: Wayfinding, the process of determining and following a route between an origin and a destination, is an integral part of everyday tasks. The purpose of this study was to investigate the impact of glaucomatous visual field loss on wayfinding behavior using an immersive virtual reality (VR) environment. Methods: This cross-sectional study included 31 glaucomatous patients and 20 healthy subjects without evidence of overall cognitive impairment. Wayfinding experiments were modeled after the Morris water maze navigation task and conducted in an immersive VR environment...

PURPOSE: One suggested advantage of human binocular vision is the facilitation of sophisticated motor control behaviours via stereopsis - but little empirical evidence exists to support this suggestion. We examined the functional significance of stereopsis by exploring whether stereopsis is used to perform a highly skilled real-world motor task essential for the occupational practice of dentistry. METHODS: We used a high fidelity virtual reality simulator to study how dentists' performance is affected by the removal of horizontal retinal image disparities under direct and indirect (mirror) observation...

PURPOSE: To compare two different diffractive trifocal intraocular lens (IOL) designs, evaluating longer-term refractive outcomes, visual acuity (VA) at various distances, low contrast VA and quality of vision. PATIENTS AND METHODS: Patients with binocularly implanted trifocal IOLs of two different designs (FineVision [FV] and Panoptix [PX]) were evaluated 6 months to 2 years after surgery. Best distance-corrected and uncorrected VA were tested at distance (4 m), intermediate (80 and 60 cm) and near (40 cm)...

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PURPOSE: Report on the safety, efficiency and refractive outcomes of LASIK surgery in patients aged 65 or older. METHODS: This study includes a case series of patients ≥65 years that underwent corneal refractive surgery during the period June 2010 to June 2015 at Hospital Zambrano Hellion, Monterrey, Mexico. Inclusion criteria were normal topography, central corneal thickness >500 μm, preoperative manifest refraction spherical equivalent (MRSE) up to -8...

The continuous perception of motion-through-depth is critical both for navigation and interacting with objects in a dynamic three dimensional (3D) world. Here we used 3D tracking to simultaneously assess the perception of motion in all directions, facilitating comparisons of responses to motion-through-depth to frontoparallel motion. Observers manually tracked a stereoscopic target as it moved in a 3D Brownian random walk. We found that continuous tracking of motion-through-depth was selectively impaired, showing different spatiotemporal properties compared to frontoparallel motion tracking...

BACKGROUND: Neural compensatory mechanisms have been proposed, which preserve the binocular visual field in glaucoma, as well as cognition in Alzheimer's disease and motor function in Parkinson's disease. It is conceivable that comparable mechanisms operate to preserve function in congenital and/or dystrophic disease. In hereditary colour vision deficiency (CVD), we observed significant facilitation in the amplitude of the binocular cone-specific visual evoked potential (VEP) compared to the monocular amplitude for the cone type corresponding to the CVD...

The author explores the concept of comfort in relation to the setting. The concept of comfort, an unusual word in the psychoanalytic lexicon, describes the intuitive and complex experience of patient and analyst being together in the analytic office. The couch and the chair are not the only tools of the setting, but they are potential instruments with which to study the therapeutic process, both in high-frequency therapy and in lower-frequency treatments. To describe the transformations that an alternative experience of comfort can promote, the author looks at the intersection of this concept with the body-mind relationship and with the Bionian concept of binocular vision...

Infant nystagmus sydrome presents as involuntary eye movement disorder and can affect seriously ocular function. We performed a retrospective study of clinical data and FRMD7 genetic test results in 12 cases of infantile nystagmus syndrome to correlate waveform, stereopsis, and visual acuity. The patients (age 6.40±2.67 years) had FRMD7 mutations as follows: missense in eight cases, shear in two cases, frameshift in one case, and non-frameshift in one case. Horizontal jerk waveform was observed in six cases, versus horizontal pendulum in five cases and dual jerk in one case...

The special sensory, motor, and cognitive capabilities of mammals mainly depend upon the neocortex, which is the six-layered cover of the mammalian forebrain. The origin of the neocortex is still controversial and the current view is that larger brains with neocortex first evolved in late Triassic Mammaliaformes. Here, we report the earliest evidence of a structure analogous to the mammalian neocortex in a forerunner of mammals, the fossorial anomodont Kawingasaurus fossilis from the late Permian of Tanzania...

Purpose: Amblyopia is a common developmental visual impairment characterized by a substantial difference in acuity between the two eyes. Current monocular treatments, which promote use of the affected eye by occluding or blurring the fellow eye, improve acuity, but are hindered by poor compliance. Recently developed binocular treatments can produce rapid gains in visual function, thought to be as a result of reduced interocular suppression. We set out to develop an effective home-based binocular treatment system for amblyopia that would engage high levels of compliance but that would also allow us to assess the role of suppression in children's response to binocular treatment...

Objective: To observe the influence on spectacle independence, satisfaction and visual function after cataract surgery monovision with different ADD. Methods: Prospective clinical study. All patients were collected from the department of ophthalmology, Shanghai JiaoTong University Affiliated Sixth People's Hospital who were diagnosed as bilateral cataract from Oct. 2013 to Mar. 2015. This study comprised 64 cases (128 eyes). All consecutive patients scheduled to undergo bilateral cataract phacoemulsification and implantation of a monofocal AcrySof IQ IOL...

Our perception of depth is substantially enhanced by the fact that we have binocular vision. This provides us with more precise and accurate estimates of depth and an improved qualitative appreciation of the three-dimensional (3D) shapes and positions of objects. We assessed the link between these quantitative and qualitative aspects of 3D vision. Specifically, we wished to determine whether the realism of apparent depth from binocular cues is associated with the magnitude or precision of perceived depth and the degree of binocular fusion...

PURPOSE: To report the frequency of binocular vision (BV) anomalies in children with specific learning disorders (SLD) and to assess the efficacy of vision therapy (VT) in children with a non-strabismic binocular vision anomaly (NSBVA). METHODS: The study was carried out at a centre for learning disability (LD). Comprehensive eye examination and binocular vision assessment was carried out for 94 children (mean (SD) age: 15 (2.2) years) diagnosed with specific learning disorder...

BACKGROUND: This report describes a rapid method of vision correction used by Special Operations Medics in multiple operational engagements. METHODS: Between 2011 and 2015, Special Operations Medics used an algorithm- driven refraction technique. A standard block of instruction was provided to the medics, along with a packaged kit. The technique was used in multiple operational engagements with host nation military and civilians. Data collected for program evaluation were later analyzed to assess the utility of the technique...