The effectiveness of hyperopia correction by wearing contact lenses in school-age children in the long-term follow-up

Background. Glasses and correction by wearing contact lenses are well tolerated by children with mild to moderate ametropia. In ametropia of high degree, an improvement of mo­nocular visual acuity with a contact lens compared to correction by glasses is 3.8 times higher. Materials and methods. The study included 56 children (112 eyes) aged 6 to 16 years with hypero­pic refraction and astigmatism, who used soft silicone hydrogel contact lenses to correct ametropia. In these patients, visual acui­ty, objective and subjective clinical refraction, axial length of the eye, corneal thickness and diameter, keratometry indicators were investigated, as well as phorometric data (accommodation, vergence, disparity areas of the oculomotor system and their inte­raction) in the early and late observation periods. Results. When using contact lenses for correction in school-age children with hyperopia and hyperopic astigmatism, after 3 years of observation there was a statistically significant increase in uncorrected visual acuity by 85 % (t = 7.9; p < 0.01), corrected visual acuity by 7 % (t = 7.4; p < 0.01), keratometry indicator in the weakest meridian by 1 % (t = 6.1; p < 0.01), in the strongest meridian by 1 % (t = 8.9; p < 0.01), central corneal thickness by 4 % (t = 4.6; p < 0.01), as well as a decrease in the spherical equivalent by 38 % (t = 3.1; p < 0.01), the amplitude of accommodation by 20 % (t = 5.8; p < 0.01), the negative relative accommodation by 20 % (t = 3.0; p < 0.01), the positive relative accommodation by 18 % (t = 3.5; p < 0.01), excessive accommodative response by 64 % (t = 7.2; p < 0.01), near phoria by 33 % (t = 4.4; p < 0.01), distance phoria by 22 % (t = 2.8; p < 0.01), the accommodation convergence to accommodation ratio by 18 % (t = 3.1; p < 0.01).

An experimental study on visual tracking based on deep learning

PurposeIn the community of visual tracking or object tracking, discriminatively learned correlation filter (DCF) has gained more importance. When it comes to speed, DCF gives the best performance. The main objective of this study is to anticipate the object visually. For tracking the object visually, the authors proposed a new model based on the convolutional regression technique. Features like HOG & Harris are used for the process of feature extraction. The proposed method will give the best results when compared to other existing methods.Design/methodology/approachThis paper introduces the concept and research status of tracks; later the authors focus on the representative applications of deep learning in visual tracking.FindingsBetter tracking algorithms are not mentioned in the existing method.Research limitations/implicationsVisual tracking is the ability to control eye movements using the oculomotor system (vision and eye muscles working together). Visual tracking plays an important role when it comes to identifying an object and matching it with the database images. In visual tracking, deep learning has achieved great success.Practical implicationsThe authors implement the multiple tracking methods, for better tracking purpose.Originality/valueThe main theme of this paper is to review the state-of-the-art tracking methods depending on deep learning. First, we introduce the visual tracking that is carried out manually, and secondly, we studied different existing methods of visual tracking based on deep learning. For every paper, we explained the analysis and drawbacks of that tracking method. This paper introduces the concept and research status of tracks, later we focus on the representative applications of deep learning in visual tracking.

Eye Movement Abnormalities in Amyotrophic Lateral Sclerosis

Background and Purpose It is generally believed that eye movements are completely spared in amyotrophic lateral sclerosis (ALS). Although a series of eye movement abnormalities has been recognized in recent years, the findings are highly controversial, and the corresponding pattern has not yet been established. Furthermore, bulbar disabilities should be considered in relation to eye movement abnormalities. The present study aimed to determine whether eye movement abnormalities are present in ALS and, if so, to investigate their characteristics and their association with bulbar disability in ALS patients. Methods Patients with clinically definite, probable or laboratory-supported probable ALS (n=60) and a control group composed of their caregivers (n=30) underwent clinical assessments and standardized evaluations of the oculomotor system using videonystagmography. The gaze test, reflexive saccade test and smooth pursuit test were administered to all subjects. Results Eye movement abnormalities such as square-wave jerks, abnormal cogwheeling during smooth pursuit, and saccade hypometria were observed in ALS patients. Square-wave jerks (p<0.001) and abnormal cogwheeling during smooth pursuit (p=0.001) were more frequently observed in ALS patients than in the control subjects. In subgroup analyses, square-wave jerks (p=0.004) and abnormal cogwheeling during smooth pursuit (p=0.031) were found to be more common in ALS patients with bulbar involvement (n=44) than in those without bulbar involvement (n=16). There were no significant differences in the investigated eye movement parameters between bulbar-onset (n=12) and spinal-onset patients (n=48). Conclusion ALS patients showed a range of eye movement abnormalities, affecting mainly the ocular fixation and smooth pursuit systems. These abnormalities were observed more common in the ALS patients with bulbar involvement. Our pioneering study indicates that the region of involvement could better indicate the pathophysiological essence of the abnormalities than the type of onset pattern in ALS. Eye movement abnormalities may be potential clinical markers for objectively evaluating upper brainstem or supratentorial cerebral lesion neurodegeneration in ALS.

Columnar processing of border ownership in primate visual cortex

To understand a visual scene, the brain segregates figures from background by assigning borders to foreground objects. Neurons in primate visual cortex encode which object owns a border (border ownership), but the underlying circuitry is not understood. Here, we used multielectrode probes to record from border ownership-selective units in different layers in macaque visual area V4 to study the laminar organization and timing of border ownership selectivity. We find that border ownership selectivity occurs first in deep layer units, in contrast to spike latency for small stimuli in the classical receptive field. Units on the same penetration typically share the preferred side of border ownership, also across layers, similar to orientation preference. Units are often border ownership-selective for a range of border orientations, where the preferred sides of border ownership are systematically organized in visual space. Together our data reveal a columnar organization of border ownership in V4 where the earliest border ownership signals are not simply inherited from upstream areas, but computed by neurons in deep layers, and may thus be part of signals fed back to upstream cortical areas or the oculomotor system early after stimulus onset. The finding that preferred border ownership is clustered and can cover a wide range of spatially contiguous locations suggests that the asymmetric context integrated by these neurons is provided in a systematically clustered manner, possibly through corticocortical feedback and horizontal connections.

Radar operator’s oculomotor activity at working with group targets

Computer oculography (eye-tracking) technologies make it possible to effectively study the work of the human oculomotor system in the operator's activity in the man-machine system. The data obtained in this way helps to increase the system efficiency, especially in conditions of extreme activities associated with vital and emotional stress at a high cost of error. Within the process of the interface ergonomic design of the radar complex for detecting and tracking, the features of the human oculomotor system are considered when working with group targets.

Using a smartphone on the move: do visual constraints explain why we slow walking speed?

Viewing one’s smartphone whilst walking commonly leads to a slowing of walking. Slowing walking speed may occur because of the visual constraints related to reading the hand-held phone whilst in motion. We determine how walking-induced phone motion affects the ability to read on-screen information. Phone-reading performance (PRP) was assessed whilst participants walked on a treadmill at various speeds (Slow, Customary, Fast). The fastest speed was repeated, wearing an elbow brace (Braced) or with the phone mounted stationary (Fixed). An audible cue (‘text-alert’) indicated participants had 2 s to lift/view the phone and read aloud a series of digits. PRP was the number of digits read correctly. Each condition was repeated 5 times. 3D-motion analyses determined phone motion relative to the head, from which the variability in acceleration in viewing distance, and in the point of gaze in space in the up-down and right-left directions were assessed. A main effect of condition indicated PRP decreased with walking speed; particularly so for the Braced and Fixed conditions (p = 0.022). Walking condition also affected the phone’s relative motion (p < 0.001); post-hoc analysis indicated that acceleration variability for the Fast, Fixed and Braced conditions were increased compared to that for Slow and Customary speed walking (p ≤ 0.05). There was an inverse association between phone acceleration variability and PRP (p = 0.02). These findings may explain why walking speed slows when viewing a hand-held phone: at slower speeds, head motion is smoother/more regular, enabling the motion of the phone to be coupled with head motion, thus making fewer demands on the oculomotor system. Good coupling ensures that the retinal image is stable enough to allow legibility of the information presented on the screen.

Which Comes First in Sports Vision Training: The Software or the Hardware Update? Utility of Electrophysiological Measures in Monitoring Specialized Visual Training in Youth Athletes

In the present study we combined popular methods of sports vision training (SVT) with traditional oculomotor protocols of Optometric Vision Therapy (OVT) and electrophysiological indexes of EEG and VEP activity to monitor training progress and changes in performance of youth ice hockey players without the history of concussion. We hypothesized that administration of OVT protocols before SVT training may result in larger performance improvements compared to the reverse order due to the initial strengthening of visual hardware capable of handling greater demands during training of visuomotor integration and information processing skills (visual software). In a cross-over design 53 youth ice hockey players (ages 13–18) were randomly assigned to one of the two training groups. Group one (hardware-software group) completed 5 weeks of oculomotor training first followed by 5 weeks of software training. For group 2 (software-hardware) the order of procedures were reversed. After 10 weeks of training both groups significantly improved their performance on all but one measure of the Nike/Senaptec Sensory station measures. Additionally, the software-hardware training order resulted in significantly lower frontal theta-to-gamma amplitude ratios on the Nike/Senaptec test of Near-Far Quickness as well as in faster P100 latencies. Both training orders also resulted in significant decreases in post-treatment P100 amplitude to transient VEP stimuli as well as decreased theta-gamma ratios for perception span, Go/No-Go and Hand Reaction time. The observed changes in the electrophysiological indexes in the present study are thought to reflect greater efficiency in visual information processing and cognitive resource allocation following 10 weeks of visual training. There is also some evidence of the greater effectiveness of the software-hardware training order possibly due to the improved preparedness of the oculomotor system in the youth athletes for administration of targeted protocols of the Optometric Vision Therapy.

Validation of a modified version of the adult developmental eye movement test

This study evaluates in terms of reliability, internal consistency, and validity a modification of the Adult Developmental Eye Movement (ADEM) test, ADEM with distractors (ADEMd), designed to analyse oculomotor system, visual processing and visual attentional behaviour. 302 healthy subjects participated in the study (20–86 years old). Intrasession repeatability was evaluated by analysing the correlation between the time needed to read different parts of the test. Inter-session analyses were carried in 40 subjects by calculating intraclass correlation coefficients and using the Bland–Altman method. Validity was assessed in the outcomes obtained according to age as well as investigating the correlation between ADEMd and attentional useful field of vision (UFOV) test. Correlation coefficients between times need to read each sheet were ≥ 0.95 (p < 0.001). The inter-session intraclass correlation coefficient ranged from 0.81 in the horizontal distractor sheet to 0.97 in the vertical sheet. Bland–Altman analysis showed clinically acceptable limits of agreement. Statistically significant correlations were found between age and ADEMd outcomes (r ≥ 0.55, p < 0.001). Processing velocity, divided attention and selective attention measured with the UFOV were correlated with the horizontal distractor times (r ≥ 0.32, p < 0.001). ADEMd test may be a useful clinical tool to evaluate the combined interaction of ocular movements and visual attentional behaviour.

Physiological aspects of visual information perception of the oculomotor apparatus

The individual characteristics of the human visual apparatus are associated with the anatomical and psychophysiological parameters of his body. Based on the EyeTracking technology, the physiological aspects of the perception of visual information by the oculomotor apparatus, which are not associated with active cognitive activity, have been investigated. The individual features in the size of fixation when reading text and examining halftone graphic objects in various people have been investigated. The time durations of fixations in different people, associated with the process of accommodation, as well as the internal structure of fixations, were investigated. It is shown that the trajectory of the gaze shift in fixation has an internal heterogeneous structure. The total trajectory of eye movement in the fixation area is determined by a set of successive clusters. This fixation structure is apparently associated with the processes of restoration of the photosensitivity of rhodopsin in the photoreceptors of the retina. All the above studies of the fixations of various subjects on the basis of various images showed that the oculomotor system, taking into account the physiological characteristics of the visual apparatus, is equally controlled by the "video processor" of the brain when the eye is accommodated to the image elements. And the only objective individual feature of human vision, which uniquely characterizes the perception of graphic information, is the value of the average displacement in fixation. It is she who is the "visiting card" of the subject and remains practically unchanged both when reading and when examining halftone images and in test validation with forced fixation of the gaze.