PURPOSE The use of handheld smart phones for written communication is becoming ubiquitous in modern society. The relatively small screens found in these devices may necessitate close working distances and small text sizes, which can increase the demands placed on accommodation and vergence. METHODS Font size and viewing distance were measured while subjects used handheld electronic devices in...

INTRODUCTION The individual and combined effect of occupational noise and vibration exposures, on workers' health has not been thoroughly investigated. In order to find better ways to prevent and manage workers' headache, this study aimed to investigate the effects of occupational noise and vibration exposure on headache/eyestrain. METHODS We used data from the fourth Korean Working Condition...

BACKGROUND The extensive use of computers as medium of teaching and learning in universities necessitates introspection into the extent of computer related health disorders among student population. AIM This study was undertaken to assess the pattern of computer usage and related visual problems, among University students in Ajman, United Arab Emirates. MATERIALS AND METHODS A total of 500 ...

ONE of the most difficult therapeutic problems for the ophthalmologist at the present time is that of headaches associated with eye strain. The majority of these are associated with heterophoria and standard therapy has been disappointing. The initial response to drugs, e.g. atropine, and cholinesterase inhibition, has not been impressive and relapse after a while has been the rule. Costenbader...

Citation for published version (APA): Hedayatpour, N. (2008). Multisite electromyographic analysis of quadriceps muscle during exerciserelated fatigue, pain and recovery. General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise...

In an effort to further expand the impact of VR technology, we developed a new implementation of an existing technique that allows widely accessible consumer-level tablets to display perspectivecorrected 3D (Fish Tank Virtual Reality or FTVR) images. To assess the usability of the technique, we conducted a human study using a visual search task previously developed for desktop FTVR systems. We ...

In a series of experiments, proofreading performance was consistently better with positive polarity (dark text on light background) than with negative polarity displays (light text on dark background). This positive polarity advantage was independent of ambient lighting (darkness vs. typical office illumination) and of chromaticity (black and white vs. blue and yellow). A final experiment showe...

PURPOSE To investigate the factors associated with visual fatigue using monitors with various radii of curvature. METHODS Twenty normal healthy adults (8 men, 12 women; mean age, 26.2 ± 2.5 years) prospectively watched five types of monitors including flat, 4000R, 3000R, 2000R, and 1000R curved monitors for 30 min. An experienced examiner measured the ophthalmological factors including near p...

PURPOSE Evaluate the relationship between the postural alignment of the head and possible interference in the view of children. METHODS We evaluated 11 children between 2 and 7 years of age of both sexes, with the visually impaired, who had nystagmus and head lock position. The test Lea Grating Acuity Test® was used to collect measurements of visual acuity. This applied on two occasions: with...

Color and monochromatic liquid crystal displays (LCDs) were compared in terms of eyestrain by using a new method that uses Landolt rings for a visual perceptional test. In this method, the difference of the nearest distances to distinguish Landolt rings between before and after the usage of LCD monitors was used as the index of eyestrain. When the nearest distance for distinguishing Landolt rin...