Influence of trajectory and contrast on dynamic visual acuity in elite team sports players.

Dynamic visual acuity (DVA) is considered an essential component for studying the visual function, especially in challenging environments like team sports. Beyond frequent comparative studies, much information is still lacking about the mechanisms underlying DVA and possible differences in stimulus presentation. It is crucial to understand the performance of DVA under different conditions of contrast and trajectories to achieve more specific data and better ecological validity of measurements. Fifty-five top professional male Spanish athletes, including 23 soccer, 14 basketball, and 18 water polo players were selected. Static visual acuity (SVA) was evaluated at 5 m. DVA was determined at 2 m under combined conditions of velocity (52°/s), three trajectories (horizontal, diagonal 45° and 135°) and two contrasts (99.7% and 13%). Significant differences in most DVA conditions measurements show that the best scores correspond to horizontal, over diagonal trajectories, and high contrast. The correlation between SVA and DVA showed a different relationship depending on the contrast conditions. Professional soccer, basketball, and water polo players have similar characteristics with reference to all the DVA evaluated conditions.

Comparison of dynamic visual acuity after implantation of toric bifocal or trifocal intraocular lens in age-related cataract patients: a randomized controlled trial.

Purpose: To investigate the dynamic visual acuity (DVA) after implantation of toric bifocal or trifocal intraocular lens in age-related cataract patients. Methods: This was a prospective randomized controlled trial. Of one hundred and twenty-four patients enrolled and randomized to receive unilateral phacoemulsification and toric trifocal (939 M/MP, Carl Zeiss Meditec AG, Jena, Germany) or toric bifocal (909 M, Carl Zeiss Meditec AG, Jena, Germany) intraocular lenses (IOL) implantation, ninety-nine patients completed the follow-up and were included in final analysis. Postoperatively, uncorrected and corrected distance (UDVA and CDVA), intermediate (UIVA and DCIVA) and near (UNVA and DCNVA) static visual acuity, manifest refraction and uncorrected and corrected distance DVA (UDDVA and CDDVA) at 20, 40 and 80 degrees per second (dps) were evaluated at one week, one month and three months. Results: Three months postoperatively, the UDVA were 0.13 ± 0.11 and 0.14 ± 0.13 in the toric trifocal and bifocal IOL group, respectively. Significant better UIVA (trifocal, 0.17 ± 0.13 vs. bifocal, 0.23 ± 0.13, p = 0.037) and DCIVA (trifocal, 0.16 ± 0.11 vs. bifocal, 0.20 ± 0.12, p = 0.048) were observed in patients implanting toric trifocal than bifocal IOL at three months postoperatively. Patients implanted with toric bifocal IOL obtained better CDDVA at 80 dps (0.5607 ± 0.2032) than the trifocal group (0.6573 ± 0.2450, p = 0.039) at three months. Postoperative UDDVA and CDDVA at 20, 40 and 80 dps were significantly associated with age (p < 0.05, respectively) and postoperative static visual acuity (p < 0.05, respectively). Conclusion: Toric trifocal IOL provides better static intermediate visual acuity, and toric bifocal IOL implantation provides better distance dynamic visual acuity at high speed.

Association of sports vision with age, gender, and static visual acuity among nonathletic population.

PURPOSE: Excellent vision is essential to performing well in sports. Sports vision includes visual, perceptual, cognitive, and oculomotor tasks that enable athletes to process and respond to what is seen. We aimed to examined how sports vision parameters - dynamic visual acuity (DVA), eye movement (EM), peripheral vision (PV), and momentary vision (MV) - varied with age and sex and assessed how static visual acuity (SVA) affect sports vision performance. MATERIALS AND METHODS: Sports vision was assessed at 45 cm distance at best-corrected SVA in 310 nonathletic participants (age, 6-60 years). Among these 310 participants, 108 university students underwent their sports vision test at 45 cm and 2.5 m distance, with and without glasses. The 4 sports vision parameters were measured by Athlevision software package installed to a laptop. Two-way analysis of variance (ANOVA) was used to compare sports vision performance in relation to age group and sex. Repeated-measures ANOVA with 1 within-factor (4 conditions) were used to analyze how sports vision varied among the near/far distance with/without glasses conditions. RESULTS: DVA increased during childhood, peaked during the 20s or 30s, and gradually decreased during middle age (P < 0.0001). DVA was significantly better in males than in females (P = 0.0001). The other 3 sport vision parameters - EM, PV, and MV - exhibited similar age trends (P < 0.001) but did not differ between two sexes. The university students with mild myopia had similar DVA, EM, and PV at both near and far distances, with and without correction; but moderate or severe myopic students with uncorrected vision had worse DVA, EM, and PV at 2.5 m than at 45 cm. CONCLUSION: Low SVA in uncorrected myopia significantly interferes the performance in sport vision tests applied in this study, especially in far distance. Improve static vision, such as myopic correction, may significantly improve sports vision, which is important in athletic performance and safety.

Advances in dynamic visual acuity test research.

The dynamic visual acuity test (DVAT) is a functional evaluation tool for the impairment and compensation of the vestibular system, which could reflect the Vestibulo-ocular reflex (VOR) function. We present an overview of DVAT research, displaying recent advances in test methods, application, and influencing factors; and discussing the clinical value of DVAT to provide a reference for clinical application. There are two primary types of DVAT: dynamic-object DVAT and static-object DVAT. For the latter, in addition to the traditional bedside DVAT, there are numerous other approaches, including Computerized DVAT (cDVAT), DVAT on a treadmill, DVAT on a rotary, head thrust DVA (htDVA) and functional head impulse testing (fHIT), gaze shift dynamic visual acuity with walking (gsDVA), translational dynamic visual acuity test (tDVAT), pediatric DVAT. The results of DAVT are affected by subject [occupation, static visual acuity (SVA), age, eyeglass lenses], testing methods, caffeine, and alcohol. DVAT has numerous clinical applications, such as screening for vestibular impairment, assessing vestibular rehabilitation, predicting fall risk, and evaluating ophthalmology-related disorders, vestibular disorders, and central system disorders.

Vision function of pseudophakic eyes with posterior capsular opacification under different speed and spatial frequency.

PURPOSE: To investigate the characteristics of dynamic visual acuity (DVA) and contrast sensitivity (CS) in pseudophakic patients with posterior capsular opacification (PCO). METHODS: Fifty-four eyes (36 patients) with PCO planned for laser capsulotomy were recruited. They underwent examinations of static visual acuity (SVA), DVA, CS and optical quality analysis (OQAS) before and one week after the laser treatment. Improvements in each index after laser treatment were analyzed. The visual quality of patients with good initial vision was studied separately. RESULTS: SVA, DVA and CS all significantly increased after capsulotomy (P < 0.05). Postoperative improvements in DVA were higher than in SVA, but they decreased when the speed increased. DVA at 15 dps gained the most improvement after capsulotomy. DVA at all analyzed speeds was significantly lower than SVA (P = 0.000). There was a significant speed-dependent decrease in DVA at lower speeds compared with higher speeds. The postoperative improvements in CS decreased when the spatial frequency was increased. The CS at the lower frequencies of 3 cpd and 6 cpd was the most improved after capsulotomy. CS was much lower at high frequencies (p < 0.05). There was a significant decrease in CS at higher spatial frequencies compared with lower frequencies. DVA improvements were correlated with CS improvements at medium spatial frequencies and with objective scattering index and Strehl ratio. The CS at all frequencies significantly improved for patients with good initial vision. CONCLUSION: PCO could impair dynamic vision function, but CS was a more sensitive indication of visual complaints in patients with slight PCO.

Effect of Closed Skills Physical Activity Exercises with Dynamic Visual Task on Visual Function for Pupils with Myopia at Grade Four at Primary School / 中国康复理论与实践

Objective:To explore the effect of closed skills physical activity with additional dynamic visual task on dynamic visual acuity and static visual acuity for pupils with myopia at grade four at primary school. Methods:In September, 2019, 37 pupils with myopia at grade four in Daicheng Experimental Primary School, Suzhou City were selected. In light of mechanism of refractive system, the intervention of closed-skilled physical activity with dynamic visual task was developed. They were intervened for 16 weeks. The dynamic visual acuity and static visual acuity were measured before intervention, and eight and 16 weeks after intervention. Results:Both dynamic visual acuity and static visual acuity improved significantly in all the pupils with myopia after 16 weeks of intervention (F > 15.933, P < 0.001), both pupils with mild and moderate myopia (|t| > 3.353, P < 0.05). The static visual acuity was better in pupils with moderate myopic than with mild myopia (t = -2.830, P < 0.01). Conclusion:Closed skills physical activity with dynamic visual task could improve the visual acuity of puplis with myopia at grade four at primary school.

Effects of Physical Activities with Visual Tasks on Kinetic and Static Visual Acuity in Children / 中国康复理论与实践

Objectives To explore the effects of visual tasks added in physical activities on kinetic and static visual acuity for 6-9 years old children.Methods Children's visual function and seeing activity were analyzed and four kinds of physical activities with visual tasks were designed. From June to August, 2018, 38 pupils from a sports summer camp aged 6 to 9 years with normal vision participated in the eight-week training. Their kinetic and static visual acuity was measured before, four weeks, and eight weeks after training.Results Both kinetic and static visual acuity improved after training (F＞ 24.368, P ＜ 0.001), and the binocular static visual acuity improved more in the boys than in the girls (t＞ 2.161, P ＜ 0.05). There was a moderate positive correlation among kinetic and static visual acuity (r＞ 0.424, P ＜ 0.01).Conclusion Physical activities with visual tasks are beneficial for kinetic and static visual acuity for children aged 6-9 years, which may be an approach to promote vision health.

Impacts of Age and Gender on Vision in School Children Accepting Physical Activities / 中国康复理论与实践

Objective:To investigate the impact of age and gender on kinetic visual acuity (KVA) and static visual acuity (SVA) in school children accepting physical activities. Methods:From May, 2018 to September, 2019, 1465 school children from various schools of Suzhou City were measured SVA and KVA with standard logarithmic visual chart and KVA detector. Results:KVA increased with age as six to nine years old, and decreased as eleven to 14. KVA was better in boys than in girls (t = 5.147, P < 0.001). SVA decreased with age as six to eight years old, fluctuated as eight to eleven, and decreased as eleven to 14, especially for girls. SVA was also better in boys than in girls (t = 3.692, P < 0.001). The prevalence of myopia increased with age as six to eight years old, and increased more significantly as eleven to 14. There was a low positive correlation between age and KVA (r = 0.046, P < 0.05), and a moderate negative correlation between age and SVA (r = -0.364, P < 0.05). KVA was positively correlated with SVA (r = 0.409, P < 0.05). Age, gender, KVA, right SVA and left SVA were the factors related with SVA. Conclusion:Vision is better in school boys than in girls. There is positive correlation between age and KVA. It is necessary to develop physical exercise according to age and gender to improve vision development, especially at the sensitive stage of visual function.

Agudeza Visual Dinámica / Acuidade Visual Dinâmica / Dynamic Visual Acuity

Resumen Presentamos una revisión del tema relativo a la habilidad visual para discriminar detalles sutiles sobre objetos en movimiento (AVD: Agudeza Visual Dinámica), mostrando las diferencias más relevantes, que han sido atribuidas a esta capacidad visual en comparación con la AVE (AV estática). Actualmente, es sabido que la correlación entre AVE y AVD es baja. Además, al medir la AVD no solo evaluamos la mínima separación espacial que el sistema visual puede resolver, sino también la funcionalidad del sistema oculomotor. De este modo, valorar la AVD implica medir la capacidad del ojo como buscador activo de información. Hoy sabemos que la AVD es uno de los mejores indicadores de éxito en ciertas especialidades deportivas (tenis de mesa, baseball, etc.) y que correlaciona negativamente con la siniestralidad en accidentes de tráfico. Entre los factores investigados que producen una reducción significativa de la resolución espacial dinámica destacan: (a) la velocidad del estímulo, afectando tanto a trayectorias verticales como horizontales; (b) el tiempo de exposición del estímulo; (c) la iluminación ambiental; (d) la disminución del contraste y e) la edad del sujeto. Por otra parte, se ha verificado que esta capacidad visual es susceptible de mejorar con el entrenamiento.

Resumo Apresentamos uma revisão do tema referente a habilidade visual para discriminar sutís detalhes diante de objetos em movimento (AVD: Acuidade Visual Dinâmica), mostrando as diferenças mais relevantes, que foram atribuídas a esta capacidade visual em comparação com a AVE (AV estática). Atualmente sabemos que a correlação entre AVE e AVD é baixa. Sendo assim, ao medir a AVD não somente avaliamos a mínima separação espacial que o sistema visual pode resolver, também avaliamos a funcionalidade do sistema oculomotor. Desse modo, para avaliar a AVD requer medir a capacidade do olho como buscador ativo de informação. Hoje sabemos que a AVD é um dos melhores indicadores de êxito em certas especialidades desportivas (tênis de mesa, baseball, etc.) e que se correlaciona negativamente com sinistralidade nos acidentes de trânsito. Entre os fatores investigados que produzem una redução significativa da resolução espacial dinâmica destacam: (a) a velocidade do estímulo, que afeta tanto as trajetórias verticais como horizontais; (b) o tempo de exposição do estímulo; (c) a iluminação ambiental; (d) a diminuição do contraste e (e) a idade do sujeito. Por outro lado, verificou-se que esta capacidade visual é suscetível a melhorar com treinamento.

Abstract We present a review on the visual ability to discriminate fine details of moving objects (DVA: Dynamic Visual Acuity), showing the most relevant differences, which have been attributed to this visual capacity in comparison to SVA (static visual acuity). It is known that the correlation between SVA and DVA is low. Moreover, when DVA is measured, not only the minimum spatial separation that the visual system can resolve is evaluated, but also the functionality of the oculomotor system. Therefore, assessing DVA also involves measuring the ability of the eye to actively seek information. Nowadays, it is known that DVA is one of the best indicators of success in certain sports specialties (table tennis, baseball, etc...) and that it negatively correlates with accident rates in traffic scenarios. The investigated factors that produce a significant reduction in dynamic spatial resolution are: (a) the speed of the stimulus, affecting both vertical and horizontal trajectories; (b) the stimulus exposure time; (c) ambient illumination; (d) reduction in contrast and (e) subject age. Moreover, it has been verified that this visual capacity is likely to improve with training.

Correlation of Static Visual Acuity and Kinetic Visual Acuity in Children and Its Implication to Physical Activity / 中国康复理论与实践

@#Objective To investigate the developmental characteristics of static visual acuity (SVA) and kinetic visual acuity (KVA) and the correlation between the for children. Methods From April to June, 2018, SVA and KVA of 715 children aged 6 to 10 years in Suzhou were tested with logarithmic visual chart and KVA meter. Results KVA and SVA increased with age within 6 to 9 years old, and decreased then. KVA was higher in boys than in girls (t = 4.604, P < 0.001), but not significantly different for SVA (t = 1.822, P > 0.05). There was a moderate positive correlation between KVA and SVA (r = 0.552, P < 0.01). KVA can predicted SVA (B = 0.617, P < 0.001). Conclusion KVA and SVA develop for children aged 6 to 9, and moderately positive correlate with each other. It means SVA may be improved via training of KVA.

A study of static, kinetic, and dynamic visual acuity in 102 Japanese professional baseball players.

BACKGROUND: It seemed that visual functions might have some effects on the performance of baseball players. We measured static, kinetic, and dynamic visual acuity (SVA, KVA, and DVA, respectively) of Japanese professional baseball players to ascertain whether there would be any difference in SVA, KVA, and DVA among player groups stratified according to their performance level. METHODS: The subjects were 102 male professional baseball players with a mean age of 26 years who were members of a Japanese professional baseball club from 2000 to 2009. They were stratified into three groups according to their performance level: A (players who were on the roster of the top-level team all the time throughout the study period), B (players who were on the roster of the top-level team sometimes but not all the time), and C (players who were never on the roster of the top-level team). They were interviewed for the use of corrective visual aids, and examined for SVA, KVA, and DVA. The measurements of these parameters were compared among groups A, B, and C. We also investigated and analyzed the association of KVA or DVA with player position (pitchers or fielders) and with hand dominance for batting. KVA was compared between the pitchers and the fielders because they each require different playing skills. DVA was compared between the right-handed and the left-handed batters. RESULTS: There was no statistically significant difference among groups A, B, and C. There was a statistically significant difference in KVA between the pitchers and the fielders (t-test; P < 0.05) There was no statistically significant difference in DVA between the right-handed and the left-handed batters. CONCLUSIONS: There was no significant difference in the examined visual functions among player groups with different performance levels.

Effect of myopic defocus on static visual acuity and dynamic visual acuity / 中华实验眼科杂志

Background Researches have suggested that the defocus can induce the change of static visual acuity,but whether it produce influence on dynamic visual acuity is not clear.Objective This study was to investigate the impact of myopic defocus on static visual acuity and dynamic visual acuity and explore the essential difierence between static visual acuity and dynamic visual acuity. Methods Forty volunteers were enrolled in this trial.including 20 adults with the age of 27.4±1.64 years and 20 children with the age of 11.70+1.49 years.All the eyes of subjects received regular examined to excluded the eye disease with the best corrected vision of ≥1.0 D,astigmatism of ≤0.75 D and anisometropia ＜1.50 D.+1.00 D,+1.50 D,+2.00 D,+2.50 D slasses were ware respectively for the defocus on the foundation of full correction.Dynamic visual acuity was inspected by using selfmade DVA-I training software.and static visual acuity wag tested by static visual acuity chart (Precision Vision,CAT.NO.2125).This clinical trial complied with the Helsinki Declaration and obtained the approval of Ethic Committee of Wenzhou Medical College.Written informed consent was received from each individual prior to the protocol. Results The dynamic and static visual acuities were gradually decreased with the elevation of defocus (F=506.907,P=0.000).No significant differences were found between static visual acuity and dynamic visual acuity in adult or children at various defocus(P＞0.05).The regression linear analysis showed that a positive correlation between static visual acuity with defoeus(R2=0.819,t=26.72,P=0.000) or dynamic visual acuity with defoeus(R2=0.826,t=27.42,P=0.000).The slope and intercept between defocus with static visual acuity were steeper than that between defocus and dynamic visual acuity (slope:F=34.18,P=0.000;intercept:F=1005.56,P=0.001). Conclusion The effect of defocus on static visual acuity is different from that of dynamic visual acuity.It could be speculated that dynamic visual acuity is related not only to refractive systems but also other factor.