Accommodation System Research Articles

The Relationship of Various Forms of Accommodative Asthenopia with the Characteristics of the Professional Activity in Patients with Visually Intense Work and the Phenomena of Computer Visual Syndrome

Purpose: to study the relationship of various forms of accommodative asthenopia (AA) with the characteristics of the professional activity of patients with visually stressful work (VSW) with the phenomena of computer visual syndrome (CVS).Methods. There were 150 patients with VSW — professional users of personal computers (mean age 28.8 ± 1.4 years) with myopic refraction (mean value of spherical equivalent 2.8 ± 1.1 diopters) under observation. The patients were divided into three groups: “normal” (50 patients); asthenic form of accommodative asthenopia (AFAA, pathology, 50 patients); habitual excessive tension of accommodation (HETA), pathology, 50 patients). All patients underwent a comprehensive ophthalmological examination for 13 parameters. As a basic diagnostic method, a specially developed questionnaire aimed at assessing professional activity was used. Statistical analysis of the results of the study was performed on the basis of an assessment of the average values of the correlation coefficients (ACC) between the patient’s responses (in points) and the studied indicators of the visual system.Results. High ACC were determined on issues characterizing the amount of daily visual load. However, no differences were found between APAA and HETA. The occurrence of AFAA is more often associated with the input of information, HETA — with reading. Evaluation of issues related to the regularity of the use of optical correction revealed differences in ACC (p < 0.05) between the “normal” group and the “pathology” groups, while in the “normal” group, optical correction was used in most cases “often” or “constantly”, in the “pathology” groups — “sometimes”.Conclusion. The results of the correlation assessment of the relationship between various types of AA in patients with VSW with the characteristics of professional activity and the parameters of the visual analyzer indicate the leading role of the duration and nature (input, reading of information) of daily work at a personal computer. One of the leading risk factors for the development of AA is inadequate optical correction. At the same time, there were no significant differences between AFAA and PINA. The most informative parameters of the accommodative system of the eye are the volume of absolute and relative accommodation (by the subjective method), as well as the coefficients of microfluctuations and stability of accommodogram (by the objective accommodation method).

Providing Reproducibility and objective control in computer measurement of fusion reserves

As is known, the main indicators of the stable functioning of fusion mechanisms – the physiological basis of binocular perception – are the fusion reserves (FR), an accurate assessment of which is still problematic. To measure the FR, a small mismatch between the accommodation and vergence systems is introduced and gradually increasing to reach certain critical angles at which the fusion mechanisms cease to function, as judged by the subjective sensations of the subjects reporting the break of the binocular image into two monocular ones. The subjectivity of such assessments of FR, as well as poorly studied dependence of FR on the parameters of test objects and measurement procedures, make it difficult to determine standard values and to create databases on RF. To overcome these shortcomings inherent in traditional methods of measuring RF, at the end of the last century, attempts were made to use computer methods (Rozhkova et al., 1996 ab, 1998). This article presents the results of a critical evaluation of the computer method for measuring FR using the author’s interactive computer program FUZIYA (Bolshakov, Rozhkova, 2013), which provides for the generation of variable test images on a special display designed for the polarization method of separating the left and right channels of test object presentation. The purpose of this study was to evaluate the accuracy and reproducibility of the measurement results, as well as to test the effectiveness of the previously proposed method to programmatically provide objective control of the binocular image break. The data obtained confirm the prospects of the approach used and make it possible to clarify the specific forms of its rational application.

Excimer Laser Correction of Myopia in Patients with Visually Intense Work — Is It Necessary to Determine the Form of Accommodative Asthenopia?

Рurpose — to study the frequency of occurrence of various forms of accommodative asthenopia (AA) in patients with visually stressful work (VSW) with different degrees of myopia planning LASIK.Methods. As part of the preoperative examination, 300 patients with VSW were under observation. There were three groups of equal age and gender, corresponding to weak (up to 3.0 diopters, 100 patients), moderate (3.25–6.0 diopters, 100 patients ) and high (6.25–8.0 diopters, 100 patients) degrees of myopia. All patients underwent objective accommodation using the Righton Speedy-I device (Japan) with further calculation of the coefficient of microfluctuations of the ciliary muscle of the eye (KMF). Diagnosis of the type of AA was carried out according to the following indicators: with KMF less than 53.0 rel. un. — asthenic form of accommodative asthenopia (AFAA), pathology; at KMF from 53.0 to 58.0 rel. — norm; at KMF more than 58.0 rel.un. — Habitual Excessive Tension of Accommodation (HETA), pathology.Results. The incidence of AA (any form) was 51–57 % and weakly depended on the degree of myopia. A significant increase (compared with the literature data) in patients with AA according to the results of this work is due to the following factors: the examination of patients exclusively with VSW, who daily perform professional visual activity at the time of the examination, as well as a wide (24–34 years) the age range of the subjects. The probability of occurrence of HETA and AFAA is quite comparable and amounted to 29–36 % and 21–23 %, respectively. The obtained results are illustrated by typical accomodograms. Conclusion: the high incidence of both forms of AA actualizes further research aimed at assessing the dynamics of the state of the accommodative system of the eye after excimer laser surgery for myopia, as well as the development of a method for correcting AA, taking into account a personalized approach that allows performing the correct diagnosis of various forms of AA (HETA, AFAA), which, ultimately, will provide adequate treatment from the position of choosing both the actual method (physical factor) and the required optical, amplitude and time parameters of exposure.

Defocus flicker of chromatic stimuli deactivates accommodation.

Tunable lenses, optical elements able to change their optical power within milliseconds, constitute an emerging technology increasingly used in ophthalmic applications. In this study, 25 subjects looked through tunable lenses at a chromatic stimulus to evaluate the perceptual response of the human visual system to periodic changes in defocus of 0.25D of amplitude and 15 Hz of temporal frequency. These defocus changes produce flicker and chromatic distortions that change with the overall level of defocus. The task in this study was to minimize the flicker by varying the average optical power, and it was performed for different myopic and hyperopic starting points. Subjects also performed a blur-minimization task in a black-and-white stimulus of the same geometry. The flicker-minimization task is more repeatable than the blur-minimization task (standard deviations ±0.17D and ±0.49D). The time per repetition of the flicker-minimization task is only 38s. Cycloplegia severely affects the blur-minimization, but not the flicker-minimization task, confirming that defocus flicker deactivates the accommodative system. This discovery can be used to develop new methods for measuring the refractive error of the eye that does not require supervision and can potentially improve existing subjective methods in terms of accuracy, precision, and measurement time.

Modern aspects of diagnosis and treatment of subjective manifestations and accommodation disorders in patients — professional users of personal computers (systematic review)

A systematic review was performed in the RSCI and PubMed databases using the following keywords: Computer vision syndrome, Digital eye strain, Accommodation, Accommodative asthenopia, RTS, and Quality of life. Eligible articles were evaluated in accordance with the criteria for prospective or retrospective studies. A total of 792 sources were analyzed, further using systematic review filters and authors knowledge of the topic. The retrospective analysis spanned 7 years (20162022). Data indicated that accommodative asthenopia (AA), as a functional visual disorder, is a natural state of the accommodative system of the eye caused by long-term exposure to visually intense work on a personal computer. AA is characterized by a wide range of subjective manifestations (complaints) and indicators of the examination of the patients vision, associated primarily with objective accommodation. A differentiated approach to the diagnosis of various forms of AA, such as habitual excessive stress of accommodation and asthenic form of accommodative asthenopia, is important to provide adequate treatment based on methods with direct physical effects on the eye (such as low-energy laser radiation, magnetophoresis, and stimulation of accommodation), opto-reflex treatment, and an outpatient course as part of home training.

Sedimentary characteristics of sandy braided river deposits and factors controlling their deposition: A case study of the lower Shihezi Formation in the northern ordos basin, China

Fluvial sandstones have been identified as significant reservoirs due to their importance in global hydrocarbon exploration. The current study investigated the sedimentary characteristics and temporal evolution of sandy braided river systems as well as the factors controlling their deposition in the Lower Shihezi Formation (H1-1 to H1-4 sub-member) of the Xinzhao area in the northern Ordos Basin using well logs, core intervals, whole rock geochemical data, and other measured reservoir parameters. Within the braided river deposits, five architectural elements were identified: multistory braided channel, single-story braided channel, sandy braid bar, overbank, and floodplain. The evolution of architectural elements in the Lower Shihezi Formation is closely related to paleoclimatic conditions and tectonic activity. Climate influences sediment accumulation through its effect on terrestrial detrital input, and tectonism influences stacking patterns and architectural style by influencing subsidence rates and accommodation changes. High sediment deliveries and high-energy hydrodynamic conditions in warm and humid climates, combined with low subsidence rates and low accommodation/sediment supply (A/S) ratios, can result in the formation of highly amalgamated braided channels and braid bars as well as complex vertical stacking patterns and aggradational processes in the H1-2 and H1-3 sub-members. Conversely, the dry and hot climates, high subsidence rates and associated high A/S ratios are responsible for the low detrital influx input, stacking of isolated sand bodies, and high preservation of overbank and floodplain deposits in the H1-4 sub-member. Considering the accommodation-based systems tracts, we contend that climate and tectonism both have a significant impact on the evolution and architectural styles of sandy braided river deposits. It is suggested that climates control the stacking pattern of fluvial sand bodies during high accommodation systems tracts, whereas both climates and accommodation spaces influence architectural styles and the degree of sand body amalgamation during low accommodation systems tracts. Considering the thick, highly amalgamated sand bodies with better reservoir properties and high vertical and lateral connectivity in the H1-2 and H1-3 sub-members, we posit that these stacked multistory sand bodies should be the preferential targets for hydrocarbon exploration. The findings of this study can further elucidate the architectural styles and factors that influence the deposition of sandy braided river systems under complex tectonic and climatic conditions.

Employee Retention in Luxury Accommodation Business in Da Nang, Viet Nam

Employee retention, a strategy towards sustainable development of each enterprise, affects greatly its productivity, quality and efficiency. This paper employs primary data collected from questionnaire, both in online and face-to-face forms, of 390 employees working in high-class accommodation system in Da Nang – Viet Nam. Using quantitative analysis techniques of scale testing, exploratory factor analysis, and multivariable regression analysis, we found that there are 9 major factors having positive effects on employee retention in luxury accommodation business system in Da Nang – Viet Nam. These factors, both material and non-material, include, from higher to lower levels: welfare, salary; manager’s support; corporate social responsibility; recognition and reward; working environment; promotion opportunities; training and development; working conditions.

Optimal Charging Control of Energy Storage Systems for Pulse Power Load Using Deep Reinforcement Learning in Shipboard Integrated Power Systems

In this paper, the charging control of the energy storage system for the pulse power load accommodation in a shipboard integrated power system (SIPS) is formulated as an optimal control problem. The SIPS is an input-affine nonlinear system with randomness and fast dynamics. The improved twin-delayed deep deterministic policy gradient (TD3) algorithm -one of the deep reinforcement learning (DRL) algorithms, is proposed to solve this optimal control problem. The proposed DRL-based control solution considers the issues regarding the reward function design and input and ramp rate constraints handling for control variables. The proposed approach linked the optimal control and DRL framework. Test cases demonstrated that we could utilize DRL algorithms to control the nonlinear system with fast dynamics by following the specific reward function design, data sampling, and constraints handling techniques.

Airbnb in Latin America: A literature review from an urban studies perspective

ABSTRACT Since its appearance 12 years ago, the digital platform Airbnb has revolutionized the temporary accommodation system worldwide, leading to diverse territorial impacts beyond the tourism and hospitality industries. Despite its distinct presence in Latin America, there is no review of the existing academic literature in the region to date. Against this backdrop, the purpose of the article is to develop a literature review of Airbnb in Latin America from the critical perspective of urban studies. To do so, exploratory-descriptive research was carried out based on the review of scientific publications that addressed the topic of Airbnb, up to and including 2020, in four international academic journal databases: Scopus, Dialnet, Scielo and Redalyc. The main results show that the existing literature on Airbnb in urban studies in Latin America is still at an early stage, with little development compared to that of other world regions, where the tourism and business model approaches seem to occlude other facets of the phenomenon. These results made it possible to outline a future research agenda on temporary accommodation in the region.

Visual Rehabilitation in Post Mild Traumatic Brain Injury. Case-Based Review

Background: Traumatic brain injury (TBI) can cause visual dysfunction affecting binocularity, spatial orientation, posture, and balance. Currently, there are several options for treating manifested visual disturbances; vision therapy is one of the possible treatment options. Methods: A 14-year-old female fainted and sustained trauma to the upper-temporal part of her right eyebrow. The patient presented with eye pain, a decreased visual field, and blurred vision and she exhibited great difficulties when reading. Both neurological tests and exploration of the anterior and posterior ocular segments showed results within normal limits. The patient was diagnosed with fusional vergence dysfunction, associated with accommodative infacility and oculomotor dysfunction. To eliminate her symptoms, a visual rehabilitation program was implemented; it consisted of accommodative, anti-suppressive, vergential, motility, hand–eye coordination, and peripheral vision exercises. Results: The symptoms manifested by the patient gradually dissipated throughout the course of therapy. However, not all optometric parameters reached normal values after visual therapy, which could indicate a traumatic injury that limited the achievement of normal optometric ranges. Conclusions: After a mild traumatic brain injury (mTBI), it is necessary to carry out a complete examination of the patient’s visual function. This visual examination must include an analysis of vergences, ocular motility, and the accommodative system to obtain an accurate diagnosis. The outcomes of the present clinical case imply that visual therapy should be considered as a treatment in cases of mTBIs.

Нейросетевой анализ функциональной трансформации зрительной системы при нормальном старении

Purpose. To reveal functional transformation patterns of the visual system in normal aging using neural network analysis. Material and methods. We examined 170 people aged 18 to 60 with objective refraction (under conditions of cycloplegia) from +5.5 D to –5.5 D. The criteria for selecting patients in the study groups were: maximally corrected visual acuity in the distance of each eye on a decimal scale of 1.0 and higher, normal color perception, absence of concomitant ophthalmopathology. A comprehensive assessment of the anatomical and optical eye parameters, indicators of monocular sensory reception and binocular interaction was carried out. 90 individual indicators of the visual system were used for neural network analysis with pattern recognition in a genetic algorithm with reduced dimensionality and step-by-step discriminant analysis. Results. Neural network analysis made it possible to establish the sequence of inclusion of 14 informative signs of the transformation of the visual system during normal aging. The contribution to the transformation of the visual system from changes in the accommodation system was 52%, from a decrease in the level of binocular interaction – 22%, changes in the function of the pupillary diaphragm – 13%, an increase in the temporal characteristics of sensory reception and signs of fatigue of the visual system – 11%. Conclusion. Neural network analysis allowed us to establish the sequence of inclusion of 14 informative signs of transformation of the visual system in normal aging. Normal aging of the visual system is expressed not only in a decrease in accommodative ability, but also in a decrease in the level of binocular interaction and binocular summation, in an increase in the processes of functional fatigue in the process of sensory reception, accompanied by a change in the function of the pupil. Keywords: normal aging, visual system, presbyopia, artificial neural network

A theoretical model of user acceptance of blockchain-based peer-to-peer accommodation

ABSTRACT Blockchain could disrupt traditional accommodation services by enabling safe, decentralised direct connections between guests and hosts. However, how users will accept and use blockchain-based services in tourism and hospitality remains unascertained. This study explores users’ perceptions of a blockchain-based peer-to-peer accommodation system and sets a theoretical basis to conceptualise the drivers of the acceptability of such a system. By using a grounded theory approach involving theoretical sampling and three steps of coding and constant comparison procedures, this study revealed that users were drawn to the system because it delivers desirable characteristics that are absent from existing services, such as further reduction of transaction fees, instant transaction settlement, wider income distribution, data integrity, algorithm autonomy, and smart protocol. Personal and social contexts were also found to influence users’ preferences for blockchain type and system ownership models. By offering key predictors and a theoretical model of user acceptance of a blockchain-based peer-to-peer accommodation system, hence taking a bottom-up approach to complement the highly top-down extant literature, this paper allows stakeholders exploring the use of blockchain technology in the tourism and hospitality sectors to have a comprehensive understanding of the phenomenon.

The Effect of Over Minus Prescription on Negative and Positive Fusional Vergence and Amplitude of Accommodation After Watching Video at Six Meters

Background The purpose of the study was to compare the effects of a -1.00 Dioptre Sphere over minus prescription on negative fusional vergence and positive fusional vergence as well as the amplitude of accommodation in myopic individuals after watching a video at 6 meters.Aim To assess the effect of over-minus lens on the amplitude of accommodation and fusional vergence pre and post-video watching.Methods The study included 30 participants aged between 18 to 25 years who did not have any systemic or ocular-related issues. During the study the participants were given an over-correction of -1.00DS over their existing spectacle correction. They were then instructed to watch a video at a distance of 6 meters for 15 minutes. The amplitude of accommodation as well as negative and positive fusional vergence were measured before and after the 15-minute video-watching session.Results The study results indicate that there was a statistically significant change in the amplitude of accommodation in the right eye when using an over-correction of -1.00DS. However there was no statistically significant change in the fusional vergence with the minus over-correction.Conclusion It is possible that the reduction in the accommodation system observed in the study was caused by wearing the divergence lens which placed the image behind the retina resulting in retinal blur. Prolonged wear of over-minus lenses could also lead to visual fatigue which can disrupt the eye-focusing system. Therefore while prescribing a corrective lens it should be monitored carefully.

Hyperelliptic Kalman filter-based aeroengine sensor fault FDIA system under multi-source uncertainty

Aeroengine faces multi-source uncertainty while operating. To reduce the conservativeness and improve the performance of the diagnosis system in complex environments, the multi-source uncertainty environment, which consists of aeroengine epistemic uncertainty and stochastic uncertainty of the control system, is considered in this paper. Based on polynomial chaos expansion (PCE), the uncertainty of the state response and output response is quantified. In addition, by proposing the hyperelliptic Kalman filter (HeKF), the optimal estimation of state correlation and output variance is realized, and the adaptive weighting matrix is provided on this basis. Combined with the thresholds calculated by design indicators of the diagnosis system, conservativeness-reduced fault detection is achieved. Ultimately, based on the fault matching idea, the hyperelliptic Kalman filter bank (HeKFB) is established and implemented for fault isolation and accommodation. Open-loop and closed-loop numerical simulations demonstrate that the proposed HeKF-based aeroengine sensor fault detection, isolation, and accommodation (FDIA) system is efficient under multi-source uncertainty conditions. Furthermore, compared to the extended Kalman filter (EKF) and the Kalman particle filter (KPF), the HeKF-based FDIA system is less conservative, more sensitive to minor faults, and superior in guaranteeing the security and reliability of aeroengine operation.

Facies association and sequence stratigraphic analysis of the lower Cretaceous Bima Formation in Yola arm of the Upper Benue Trough, Northeastern Nigeria

The Lower Cretaceous Bima Formation is the oldest sedimentary rock in the Upper Benue Trough. This research is aimed at understanding the facies, facies association, and sequence stratigraphic framework of the continental Bima Formation. Detail field mapping, lithostratigraphic studies, petrography, and paleocurrent analysis revealed that the formation is composed of three facies associations; gravel facies association FAI (gravelly dominated), sandstone facies association FAII (sand-sandstones dominated), and fine-grained facies association FAIII and four facies successions; proximal alluvial fan facies succession, braided river facies succession, fluvio-lacustrine facies succession, and flood plain facies association. The Bima Formation is punctuated by three major bounding surfaces, these provide the means of subdividing the Bima Formation into four depositional sequences namely; SQ1, SQ2, SQ3, and SQ4. Four system tracts were also identified within the Bima Formation; aggradational and high accommodation system tracts represent positive accommodation/sediments supply, and low accommodation system tract-A and B suggest negative accommodation/sediment supply. The overall sedimentation processes in the Bima Formation are controlled by climate, tectonic subsidence, and uplift. The paleocurrent data from the northern part of the study area suggest a unidirectional flow in NNW while the southern part of the study area shows SSW direction.

Accommodation Response Variations in University Students under High Demand for Near-Vision Activity.

The objective of this study was to investigate accommodation changes and visual discomfort in a university student population after a period of high demand for near-vision activity. A total of 50 university students aged between 20 and 22 years were recruited. The tests performed involved positive relative accommodation (PRA), negative relative accommodation (NRA), accommodation amplitude (AA), and monocular and binocular accommodative facility (MAF and BAF). Visual discomfort was measured on a scale involving a visual discomfort questionnaire (VDQ). All accommodative variables underwent changes during the exam period; specifically, regarding NRA and PRA, 30.4% and 15.1% of the studied population, respectively, appeared to be below average. Moreover, 42.3% of the population exhibited values below average in the second measure of AA. On the other hand, a small percentage of the population was below average in MAF and BAF measurements: 3% in the monocular right eye test, 6% in the left eye test, and 9.1% in the binocular facility test. Finally, the VDQ score did not reveal a statistically significant difference between the two measurements. Prolonged near-distance work, such as a university exams period, changed all accommodation systems (amplitude of accommodation, relative accommodation, and accommodation facility). These changes influence an accommodation excess that results in blurred vision, headache, and problems with focusing.

Optical modelling of an accommodative light field display system and prediction of human eye responses.

The spatio-angular resolution of a light field (LF) display is a crucial factor for delivering adequate spatial image quality and eliciting an accommodation response. Previous studies have modelled retinal image formation with an LF display and evaluated whether accommodation would be evoked correctly. The models were mostly based on ray-tracing and a schematic eye model, which pose computational complexity and inaccurately represent the human eye population's behaviour. We propose an efficient wave-optics-based framework to model the human eye and a general LF display. With the model, we simulated the retinal point spread function (PSF) of a point rendered by an LF display at various depths to characterise the retinal image quality. Additionally, accommodation responses to the rendered point were estimated by computing the visual Strehl ratio based on the optical transfer function (VSOTF) from the PSFs. We assumed an ideal LF display that had an infinite spatial resolution and was free from optical aberrations in the simulation. We tested points rendered at 0-4 dioptres of depths having angular resolutions of up to 4x4 viewpoints within a pupil. The simulation predicted small and constant accommodation errors, which contradict the findings of previous studies. An evaluation of the optical resolution on the retina suggested a trade-off between the maximum achievable resolution and the depth range of a rendered point where in-focus resolution is kept high. The proposed framework can be used to evaluate the upper bound of the optical performance of an LF display for realistically aberrated eyes, which may help to find an optimal spatio-angular resolution required to render a high quality 3D scene.

Developing sustainable land-use patterns at watershed scale using nexus of soil, water, energy, and food

Aside from the many services that soil provides, it also stores water and makes it available to crops, which is critical for food security. However, the necessity of further studies for overcoming the existing gap in relation to the role of soil in the water, energy, and food nexus system has been preoccupying the experts and specialists around the world for some time. In this sense, the balance between many key ecosystem components based on the Soil, water, energy, and food (SWEF) nexus framework is one of the key characteristics of holistic and accommodative watershed management systems. To the best of our knowledge, the watershed scale is used as a planning unit for the first time in the current study to construct a conceptual model for adaptive management of optimum land-use/cover allocation using SWEF. The method was then used for the Shazand Watershed, Iran. Numerous metrics, such as soil erosion, soil organic carbon (SOC), water and energy use, mass efficiency, and economic efficiency, were investigated. Finally, a compound indicator was used to generate the SWEF nexus index (SWEFNI) for various land-uses/crops for the node year 2014. SWFENI ranged from 0.19 (worst) for rangeland to 0.78 (best) for almond plantations, according to the findings. The study's present approach may be tested worldwide.

A two-stage rolling optimization strategy for park-level integrated energy system considering multi-energy flexibility

Due to the advantages, such as being environment-friendly, the penetration of renewable energy has increased rapidly. However, the uncertainty and randomness of renewable energy source output severely impact economic dispatch, especially for those park-level integrated energy systems. To improve the economy of system operation and the accuracy of scheduling results, this paper presents a two-stage rolling dispatch strategy, in which a refined model of power flow, natural gas pipelines, and heat flow are established. The multi-energy flow model is linearized by the piecewise linearization method and second-order cone relaxation method. Moreover, a virtual energy storage model considering the thermal inertia in district heat systems and building enclosures is constructed. Further, to quantify the capacity of adjustable resources in park-level integrated energy systems, a multi-energy flexible source model is set up and integrated. Ultimately, to even out the prediction errors, a two-stage rolling dispatch is carried out, which corrects the results of day-ahead schedule plans. Based on the aforementioned works, case results demonstrate the effectiveness of the presented approach, both in renewable energy accommodation rate (with a promotion of 13.3%) and system operation economy (with a reduction of 14.55% in operation costs). It is recognized that the constructed models play important roles in improving the system flexibility and the presented operation strategy can effectively enhance the accuracy of the dispatch plans in real-time operation.

Tweenager Computer Visual Syndrome Due to Tablets and Laptops during the Postlockdown COVID-19 Pandemic and the Influence on the Binocular and Accommodative System.

The aim of our study was to compare computer visual syndrome (CVS) in a tweenager student population who use tablets and laptops only to play versus CVS in tweenagers who use these digital devices at school to study, in addition to playing. The tests performed were a validated survey for children for the detection of CVS and accommodative and vergence tests. The CVS item questionnaire was divided into four main groups based on questions concerning the following: (I) the digital device usage time, (II) musculoskeletal and ergonomic nature, (III) visual symptoms, and (IV) ocular surface symptoms. The high-demand digital device group showed worse punctuation in all item groups. From the optometric perspective, when the subjects were classified according to the CVS, high-demand participants presented a clear tendency to exophoria with statistically significant differences in distance vision (−1.94 ± 4.48 Δ) and near vision (−5.78 ± 8.62 Δ) (p < 0.01). Our results establish a relationship between the increased use of electronic devices and computer vision syndrome in the preadolescent population. In addition, this situation is related to the presence of visual, accommodative, and binocular dysfunctions that could affect the efficiency of the visual system.