The Effects of Target Borders on Dynamic Visual Acuity: Practical and Theoretical Implications

Long, Gerald M.; Garvey, Philip M.

doi:10.1068/p170745

Cited by 10 publications

(4 citation statements)

References 22 publications

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“…The velocity of stimuli characters significantly affected the minimal legible size in the present study; as the velocity of the stimulus character increased, so did the minimal legible size. This result was consistent with the findings of previous studies, including those of Long and Johnson, 44 Long and Garvey, 22,45 and Long and Crambert, 32 showing that subjects were able to resolve markedly smaller targets at a lower velocity than at a higher velocity. Additionally, the results of the present experiment were similar to those of Paakkonen and Morgan, 37 who showed that the blur discrimination threshold was a linear function of speed.…”

Section: Velocity Of Stimulussupporting

confidence: 92%

Effects of color and background luminance on minimal legible size of dynamic Chinese characters presented on a LCD monitor for low‐vision and normally sighted users

Huang

2010

J Soc Info Display

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Abstract— The effects of velocity (3, 5, and 7 cm/sec), stimulus color (red, green, and blue), and background luminance (20–80% white, in increments of 15%) on minimal legible size of dynamic Chinese characters, were examined. Participants were divided into low‐vision, severely myopic, and normal‐vision groups. They were asked to recognize the stimulus Chinese characters, which were presented with varying velocity on a screen. Analysis showed that the minimal legible size was significantly greater for those in the low‐vision and severely myopic groups than for those in the normal‐vision group, and the minimal legible size for the low‐vision group was greater than that for the severely myopic group. The minimal legible size was significantly greater when the stimuli were green than when they were red or blue; however, no significant difference was found between green and blue stimuli or between blue and red ones. An effect was observed for background luminance: a higher ratio of white in the gray background yielded a smaller minimal legible size than did a lower ratio of white. Additionally, velocity significantly affected the minimal legible size: a velocity of 3 cm/sec resulted in lower minimal legible size than did a velocity of 7 cm/sec. Results have implications for electronic text information design or icon design for visually impaired individuals.

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Section: Velocity Of Stimulussupporting

confidence: 92%

Effects of color and background luminance on minimal legible size of dynamic Chinese characters presented on a LCD monitor for low‐vision and normally sighted users

Huang

2010

J Soc Info Display

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“…Degradation of colour is not equal for all wavelengths. Red colours (longer wavelengths) are affected more than blue colours (shorter wavelengths) following dark adaption since spectral sensitivity between long-wavelength cones and short-wavelength rods and cones is different (Long and Garvey, 1988).…”

Section: Contrast Sensitivity and Low Luminancementioning

confidence: 99%

Paramedic practice in low light conditions: a scoping review

Hichisson

Wilcock

Eaton

et al. 2023

Journal of Paramedic Practice

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Background: Paramedics undertake visually demanding tasks, which may be adversely affected by low lighting conditions. Aims: The study aimed to: identify difficulties paramedics experience carrying out tasks in low light; and establish occupational health standards and adjustments that may improve working practices. Methods: A scoping review was undertaken informed by a professional panel of paramedics recruited through social media. A meta-analysis was conducted assessing visual acuity under different light levels. Findings: Difficulty in driving and in assessing/treating patients under low light conditions were reported. Sixty relevant studies were identified for review. Visual acuity reduces with decreasing luminance, causing increasing difficulties in performing critical tasks. Conclusion: Visual function testing can assess paramedics' visual health and ability to undertake critical tasks. Adjustments may help to improve conditions. Regular occupational health assessments could identify paramedics who need support. Further research should explore levels of visual function and practical adjustments needed for safe clinical practice.

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“…Con la honrosa excepción del profesor Gerald Long (Long et al 1987(Long et al , 1988(Long et al , 1989(Long et al , 1990(Long et al , 1991(Long et al , 1993(Long et al , 1998(Long et al , 2002 de la Universidad de Villanova (Pennsylvania), los trabajos más relevantes fueron desarrollados entre los años 50 y 70. La mayoría de estos estudios se centraron principalmente en determinar las influencias que sobre la AVD presentaban características del estímulo móvil como el tamaño, el contraste, la velocidad angular de desplazamiento y el tiempo de exposición.…”

Section: Concepto Relaciones E Implicacionesunclassified

“…Para decir que un instrumento tiene validez de contenido el diseñador del test debe asegurarse de su relevancia y de que la medición represente el concepto medido. En nuestro caso, el concepto es la agudeza visual dinámica, la importancia de cuya determinación vienen reclamando reiteradamente autores como Long et al (1988Long et al ( , 1998Long et al ( , 2002 .…”

Section: Introduccionunclassified

Evaluación de la Agudeza Visual Dinámica: una aplicación al contexto deportivo

Quevedo Junyent

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The importance of vision in life is unquestionable. It is because of this that optometry, as a science of vision focused in measurement and analysis of visual function, has been developing techniques and instruments to evaluate its functionality in various contexts. Sport has become a social phenomenon, as evidenced by an increasing trend towards active participation, both professionally and recreationally. In order to enhance athletic performance, many have looked towards the sciences (medicine, biomechanics, psychology) for answers. With the specialization of sports vision, optometry has been particularly useful. The importance of the science of vision relating to sports is easily justified by considering that, in general, vision plays a dominant role in athletic success since the majority of external stimuli that athletes have to react to come through the visual system. One of the most critical areas that Sports Vision incorporates is the specific screening of visual capacities related to sports performance. If we consider the dynamic characteristics of most sporting modalities that generally involve constant environmental changes, sudden and fast movements of players and ball, speed, etc., we have to accept the premise that action sports require visual performance evaluation that is different from normal vision testing, since routine testing only samples static vision. Assessment of specific sports-related visual abilities includes peripheral vision, visual reaction time or dynamic visual acuity. In reference to the evaluation of dynamic visual acuity, defined as the ability to resolve a target under conditions of relative motion between the observer and the test stimulus, it must be noted that methods developed to date for its measurement have not been, in general, psychometrically validated, and are too cumbersome and unwieldy to find a place in clinical practice or in field situations. This lack of proper equipment explains much the difficulty of establishing objective, precise and reliable measurements of a visual skill, considered, not only from the sporting context but also from road safety or aircraft operating, as one of the most predictive of real-world task performances, especially in dynamic conditions." Additionally, the need to improve our daily work giving visual attention to elite athletes in the Olympic Training Centre in Sant Cugat del Vallés has led us to develop this doctoral dissertation, with the design of the DinVA 3.0., a computer assisted test for the measurement of dynamic visual acuity. The efficacy of our instrument has been supported by four experimental studies. The first three, included into the psychophysics context, have allowed us to find the legitimacy of the DinVA test measurement by establishing its construct validity, as well as internal and temporal consistency. The last experiment is a differential study where we compared the results of dynamic visual acuity obtained by a sample of elite water polo players and a group of totally sedentary students of Optometry. The obtained results have shown that speed, contrast and direction of displacement of the stimulus significantly affect dynamic visual acuity, supporting the construct validity of the DinVA3.0. Additionally, we have verified that our instrument to measure dynamic visual acuity has a high degree of internal validity, as well as a high test-retest reliability of the obtained measures. Finally, we have been able to establish that athletic training seems to improve dynamic visual acuity. In conclusion, with this doctoral dissertation we aim at offering both, clinicians and researchers, a standardized and typified instrument that allows a solid and specific measure of dynamic visual acuity depending on the application context. It is easy to use, offers the possibility of training, and does not require more equipment than something so common and ubiquitous as a computer.

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The Effects of Target Borders on Dynamic Visual Acuity: Practical and Theoretical Implications

Cited by 10 publications

References 22 publications

Effects of color and background luminance on minimal legible size of dynamic Chinese characters presented on a LCD monitor for low‐vision and normally sighted users

Effects of color and background luminance on minimal legible size of dynamic Chinese characters presented on a LCD monitor for low‐vision and normally sighted users

Paramedic practice in low light conditions: a scoping review

Evaluación de la Agudeza Visual Dinámica: una aplicación al contexto deportivo

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