Productivity associated with visual status of computer users.
ABSTRACT The aim of this project is to examine the potential connection between the astigmatic refractive corrections of subjects using computers and their productivity and comfort. We hypothesize that improving the visual status of subjects using computers results in greater productivity, as well as improved visual comfort.
Inclusion criteria required subjects 19 to 30 years of age with complete vision examinations before being enrolled. Using a double-masked, placebo-controlled, randomized design, subjects completed three experimental tasks calculated to assess the effects of refractive error on productivity (time to completion and the number of errors) at a computer. The tasks resembled those commonly undertaken by computer users and involved visual search tasks of: (1) counties and populations; (2) nonsense word search; and (3) a modified text-editing task.
Estimates of productivity for time to completion varied from a minimum of 2.5% upwards to 28.7% with 2 D cylinder miscorrection. Assuming a conservative estimate of an overall 2.5% increase in productivity with appropriate astigmatic refractive correction, our data suggest a favorable cost-benefit ratio of at least 2.3 for the visual correction of an employee (total cost 268 dollars) with a salary of 25,000 dollars per year.
We conclude that astigmatic refractive error affected both productivity and visual comfort under the conditions of this experiment. These data also suggest a favorable cost-benefit ratio for employers who provide computer-specific eyewear to their employees.
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ABSTRACT: At a fixed viewing distance (VD), reading speed increases with print size. It is not known if this holds for computer tasks when postures are not constrained. Reflective glare on a monitor may reduce productivity. The effects of both may be modified by age. We evaluated effects of age, font size, and glare on performance for visually demanding text-based tasks on a computer. Nineteen young (18 to 35 years old) and eight older (55 to 65 years old wearing progressive lenses that correct for presbyopia) subjects participated in a study with two trial factors: font size (1.78, 2.23, and 3.56 mm) and glare (produced by bright light-emitting diode task light reflective off a matte liquid crystal display monitor). The monitor location was fixed but subjects were allowed to change their posture and move the chair. Subjects performed visual tasks that required similar visual skills to common tasks such as Internet use, data entry, or word processing. Productivity, accuracy, and VD increased as font size increased. For each 1-mm increase in font size, there was a mean productivity gain of 3 correct clicks/min and an improvement in accuracy of 2%. Font size increase also led to lowered perceived task difficulty. Adding reflective glare on the monitor surface led to a reduced VD but had no effect on productivity or accuracy. With visual corrections for presbyopia, age had no effect on these relationships. Productivity is improved when the font is increased from 1.78 or 2.23 to 3.56 mm for text-based computer tasks. The largest font size corresponds to a visual angle of font of 23.4 arcmin. This visual angle of font is above the high end of ISO recommendations (International Organization for Standardization, 1992, 2011). The findings may be useful for setting the font sizes for computers and for training office workers.Optometry and vision science: official publication of the American Academy of Optometry 05/2014; DOI:10.1097/OPX.0000000000000274 · 1.53 Impact Factor
10/2012; 56(1):2378-2382. DOI:10.1177/1071181312561514
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ABSTRACT: The use of electronic reading devices has increased dramatically. However, some individuals report increased visual symptoms when reading from electronic screens. This investigation compared reading from two electronic devices (Amazon Kindle or Apple Ipod) versus hardcopy text in two groups of 20 subjects.METHODS: Subjects performed a 20 min reading task for each condition. Both the accommodative response and reading rate were monitored during the trial. Immediately post-task, subjects completed a questionnaire concerning the ocular symptoms experienced during the task. In comparing the Kindle with hardcopy, no significant difference in the total symptom score was observed, although the mean score for the symptoms of tired eyes and eye discomfort was significantly higher with the Kindle. No significant differences in reading rate were found. When comparing the Ipod with hardcopy, no significant differences in symptom scores were found. The mean reading rate with the Ipod was significantly slower than for hardcopy while the mean lag of accommodation was significantly larger for the Ipod. Given the significant increase in symptoms with the Kindle, and larger lag of accommodation and reduced reading rate with the Ipod, one may conclude that reading from electronic devices is not equivalent to hardcopy.Work 11/2013; 47(3). DOI:10.3233/WOR-131777 · 0.52 Impact Factor