Refractive Error of Students (15- to 18-year-olds) in Northwest Mexico.

Significance: We assessed the prevalence of refractive error in a sample of children of Northern Mexico using the Refractive Error Study in Children protocol of the World Health Organization, which allows for the comparison with other global studies.

Purpose: Uncorrected refractive error is the main cause of visual impairment in children. The purpose of this study was to assess the refractive error and visual dysfunctions of students (15 to 18 years old) in the upper-middle school system of Sinaloa, Mexico.

The Effect of Zoom Magnification and Large Display on Video Comprehension in Individuals With Central Vision Loss.

Purpose: A larger display at the same viewing distance provides relative-size magnification for individuals with central vision loss (CVL). However, the resulting large visible area of the display is expected to result in more head rotation, which may cause discomfort. We created a zoom magnification technique that placed the center of interest (COI) in the center of the display to reduce the need for head rotation.

Saccade Landing Point Prediction Based on Fine-Grained Learning Method.

The landing point of a saccade defines the new fixation region, the new region of interest. We asked whether it was possible to predict the saccade landing point early in this very fast eye movement. This work proposes a new algorithm based on LSTM networks and a fine-grained loss function for saccade landing point prediction in real-world scenarios.

An implementation of Bubble Magnification did not improve the video comprehension of individuals with central vision loss.

Purpose: People with central vision loss (CVL) watch television, videos and movies, but often report difficulty and have reduced video comprehension. An approach to assist viewing videos is electronic magnification of the video itself, such as Bubble Magnification.

Methods: We created a Bubble Magnification technique that displayed a magnified segment around the centre of interest (COI) as determined by the gaze of participants with normal vision.

Orientation of the preferred retinal locus (PRL) is maintained following changes in simulated scotoma size.

Although macular lesions often enlarge, we know little about what happens when the preferred retinal locus (PRL) is enveloped by the lesion. We present a prospective study of subjects with normal vision who were trained to develop a PRL using simulated scotomas with a gaze-contingent visual display. We hypothesized that, when subjects had developed a robust PRL and the scotoma size was increased, the PRL would move to remain outside the scotoma and in a direction that maintained the orientation (theta) of the PRL relative to the fovea.

The Impact of Field of View on Understanding of a Movie Is Reduced by Magnifying Around the Center of Interest.

Purpose: Magnification is commonly used to reduce the impact of impaired central vision. However, magnification limits the field of view (FoV) which may make it difficult to follow the story. Most people with normal vision look in about the same place at about the same time, the center of interest (COI), when watching "Hollywood" movies.

Validation of a vision-related activity scale for patients with retinitis pigmentosa.

Purpose: There have been few systematic reports of vision-related activity limitations of people with retinitis pigmentosa (RP). We report a merging of data from the National Eye Institute Visual Function Questionnaire (NEI-VFQ) obtained in five previous studies. We asked whether the Vision Function Scale (VFS; Pesudovs et al.

Narrative video scene description task discriminates between levels of cognitive impairment in Alzheimer's disease.

Unlabelled: The process of interpreting and acting upon the visual environment requires both intact cognitive and visual systems. The narrative description (ND) task, initially developed to detect changes in ecologically relevant visual function in people with impaired vision, is an objective measure of the ability to perceive, understand, and describe a visual scene in a movie clip.

Objective: Because the ND task draws heavily on semantic and working memory ability in addition to basic visual perception, we aimed to assess the discriminative performance of this task across levels of cognitive impairment.

A free database of eye movements watching "Hollywood" videoclips.

The provided database of tracked eye movements was collected using an infra-red, video-camera Eyelink 1000 system, from 95 participants as they viewed 'Hollywood' video clips. There are 206 clips of 30-s and eleven clips of 30-min for a total viewing time of about 60 hours. The database also provides the raw 30-s video clip files, a short preview of the 30-min clips, and subjective ratings of the content of the videos for each in categories: (1) genre; (2) importance of human faces; (3) importance of human figures; (4) importance of man-made objects; (5) importance of nature; (6) auditory information; (7) lighting; and (8) environment type.

Microsaccades reflect the dynamics of misdirected attention in magic.

The methods of magicians provide powerful tools for enhancing the ecological validity of laboratory studies of attention. The current research borrows a technique from magic to explore the relationship between microsaccades and covert attention under near-natural viewing conditions. We monitored participants' eye movements as they viewed a magic trick where a coin placed beneath a napkin vanishes and reappears beneath another napkin.

People With Central Vision Loss Have Difficulty Watching Videos.

Purpose: People with central vision loss (CVL) often report difficulties watching video. We objectively evaluated the ability to follow the story (using the information acquisition method).

Methods: Subjects with CVL (n = 23) or normal vision (NV, n = 60) described the content of 30-second video clips from movies and documentaries.

When Watching Video, Many Saccades Are Curved and Deviate From a Velocity Profile Model.

Commonly, saccades are thought to be ballistic eye movements, not modified during flight, with a straight path and a well-described velocity profile. However, they do not always follow a straight path and studies of saccade curvature have been reported previously. In a prior study, we developed a real-time, saccade-trajectory prediction algorithm to improve the updating of gaze-contingent displays and found that saccades with a curved path or that deviated from the expected velocity profile were not well fit by our saccade-prediction algorithm (velocity-profile deviation), and thus had larger updating errors than saccades that had a straight path and had a velocity profile that was fit well by the model.

Measuring the Difficulty Watching Video With Hemianopia and an Initial Test of a Rehabilitation Approach.

Purpose: If you cannot follow the story when watching a video, then the viewing experience is degraded. We measured the difficulty of following the story, defined as the ability to acquire visual information, which is experienced by people with homonymous hemianopia (HH). Further, we proposed and tested a novel rehabilitation aid.

People with Hemianopia Report Difficulty with TV, Computer, Cinema Use, and Photography.

Significance: Our survey found that participants with hemianopia report more difficulties watching video in various formats, including television (TV), on computers, and in a movie theater, compared with participants with normal vision (NV). These reported difficulties were not as marked as those reported by people with central vision loss.

Purpose: The aim of this study was to survey the viewing experience (e.

The Preferred Retinal Locus Used to Watch Videos.

Purpose: Eccentric viewing is a common strategy used by people with central vision loss (CVL) to direct the eye such that the image falls onto functioning peripheral retina, known as the preferred retinal locus (PRL). It has been long acknowledged that we do not know whether the PRL used in a fixation test is also used when performing tasks. We present an innovative method to determine whether the same PRL observed during a fixation task was used to watch videos and whether poor resolution affects gaze location.

Dynamic gaze-position prediction of saccadic eye movements using a Taylor series.

Gaze-contingent displays have been widely used in vision research and virtual reality applications. Due to data transmission, image processing, and display preparation, the time delay between the eye tracker and the monitor update may lead to a misalignment between the eye position and the image manipulation during eye movements. We propose a method to reduce the misalignment using a Taylor series to predict the saccadic eye movement.

Changes in visibility as a function of spatial frequency and microsaccade occurrence.

Fixational eye movements (FEMs), including microsaccades, drift, and tremor, shift our eye position during ocular fixation, producing retinal motion that is thought to help visibility by counteracting neural adaptation to unchanging stimulation. Yet, how each FEM type influences this process is still debated. Recent studies found little to no relationship between microsaccades and visual perception of spatial frequencies (SF).

V1 neurons respond differently to object motion versus motion from eye movements.

How does the visual system differentiate self-generated motion from motion in the external world? Humans can discern object motion from identical retinal image displacements induced by eye movements, but the brain mechanisms underlying this ability are unknown. Here we exploit the frequent production of microsaccades during ocular fixation in the primate to compare primary visual cortical responses to self-generated motion (real microsaccades) versus motion in the external world (object motion mimicking microsaccades). Real and simulated microsaccades were randomly interleaved in the same viewing condition, thereby producing equivalent oculomotor and behavioural engagement.

Characteristics of Spontaneous Square-Wave Jerks in the Healthy Macaque Monkey during Visual Fixation.

Saccadic intrusions (SIs), predominantly horizontal saccades that interrupt accurate fixation, include square-wave jerks (SWJs; the most common type of SI), which consist of an initial saccade away from the fixation target followed, after a short delay, by a return saccade that brings the eye back onto target. SWJs are present in most human subjects, but are prominent by their increased frequency and size in certain parkinsonian disorders and in recessive, hereditary spinocerebellar ataxias. SWJs have been also documented in monkeys with tectal and cerebellar etiologies, but no studies to date have investigated the occurrence of SWJs in healthy nonhuman primates.

Fixational eye movement correction of blink-induced gaze position errors.

Our eyes move continuously. Even when we attempt to fix our gaze, we produce "fixational" eye movements including microsaccades, drift and tremor. The potential role of microsaccades versus drifts in the control of eye position has been debated for decades and remains in question today.

Task difficulty in mental arithmetic affects microsaccadic rates and magnitudes.

Microsaccades are involuntary, small-magnitude saccadic eye movements that occur during attempted visual fixation. Recent research has found that attention can modulate microsaccade dynamics, but few studies have addressed the effects of task difficulty on microsaccade parameters, and those have obtained contradictory results. Further, no study to date has investigated the influence of task difficulty on microsaccade production during the performance of non-visual tasks.

Microsaccades restore the visibility of minute foveal targets.

Stationary targets can fade perceptually during steady visual fixation, a phenomenon known as Troxler fading. Recent research found that microsaccades-small, involuntary saccades produced during attempted fixation-can restore the visibility of faded targets, both in the visual periphery and in the fovea. Because the targets tested previously extended beyond the foveal area, however, the ability of microsaccades to restore the visibility of foveally-contained targets remains unclear.