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At least 289 records · Page 16Linked to original sources

Effects of taurine supplementation on VDT work induced visual stress.

In order to evaluate the effects of dietary taurine supplementation on visual fatigue induced by visual display terminals (VDT) work, 25 male college students aged from 20 to 24 years who were not engaged in VDT work were selected to participate in the study. Volunteers were randomly assigned to either the taurine supplementation (n=13) or the placebo supplementation control group (n=12). Before and after 12 days of taurine (3 g/day) or placebo supplementation, two identical 2.5-hr VDT work tests were performed while recording the P100, N75 and N145 latencies and P100 amplitude of pattern visual evoked potential (PVEP) and the frequency of critical flicker fusion (CFF). Following 2.5-hr of VDT work, the P100 and N75 latencies of PVEP increased ( P<0.01) while the P100 amplitude decreased significantly ( P<0.01). The frequency of CFF also reduced significantly ( P<0.01). After 12 days of taurine supplementation, the reduction in P100 amplitude after VDT work alleviated significantly ( P<0.05). The results suggest that taurine supplementation alleviates visual fatigue induced by VDT work.

Adult↗

Vertical prisms. Why avoid them?

Vertical prisms are useful in the permanent or temporary alleviation of asthenopic symptoms arising from a vertical misalignment of the visual axes. A wide variety of both comitant and noncomitant hyperdeviations may be candidates for vertical prism use. Vertical prism strength is seldom difficult to compute and when properly employed, vertical prisms do not lead to unsightly spectacles.

Aged↗

Prevalence of eye disorders in young children with eyestrain complaints.

PURPOSE: To determine whether eyestrain symptoms predict eye conditions in 6-year-old children. DESIGN: Cross-sectional population-based study. METHODS: Reports of eyestrain symptoms were sought in parental questionnaires; 1740 children (79% response) underwent eye examinations (visual acuity, cover testing, cycloplegic autorefraction, and fundus examination). RESULTS: Eyestrain information was available for 1448 children; 220 (15.2%) reported eyestrain symptoms, including 60 (3.4%) who reported near work-associated headaches. Most children (82.3%) had a normal eye examination, while refractive errors, amblyopia, and strabismus were found in 15.0%, 3.6%, and 7.3%, respectively. Corresponding rates for children without eyestrain were 9.9%, 1.4%, and 1.8%, respectively. Moreover, 78.7% of children with refractive errors, 68% with amblyopia, and 58% with strabismus reported no eyestrain. CONCLUSIONS: Most children complaining of eyestrain had a normal eye examination; whereas most children with refractive error, amblyopia, or strabismus were free of eyestrain, making this complaint a poor marker of eye conditions in young children.

Asthenopia↗

Impact of the line of sight on toric phakic intraocular lenses for hyperopia.

We present a hyperopic patient with a decentered line of sight in whom the residual refractive error after toric phakic intraocular lens (TP IOL) implantation was improved by displacement and individualized treatment. A 35-year-old woman presented with asthenopic complaints 2 months after bilateral TP IOL implantation and IOL rotation 4 weeks later. Examination revealed the line of sight to be nasally and inferiorly decentered in relation to the center of the pupil. A more nasal reenclavation of the TP IOL decreased the coma, and the uncorrected visual acuity was 20/20. We conclude that line of sight should be measured before TP IOL implantation, especially in hyperopic eyes.

Adult↗

Fixation disparity analysis: sensory and motor approaches.

PURPOSE: Fixation disparity measurement as a tool for analyzing the binocular visual system has taken very different approaches in the United States and Central Europe. In the United States, testing has primarily followed a motor approach, and resulting management has followed parameters established by graphical analysis closely. In German-speaking countries, a strong sensory-based analysis has been popular for decades, utilizing equipment rarely seen in the United States. Management in these countries has been almost exclusively directed toward prismatic prescription. METHODS: This report examines the instrumentation, underlying strategies, and management used in both the motor and sensory approaches to fixation disparity analysis. Testing protocols and management options are detailed for each approach. CONCLUSION: Although both approaches agree that fixation disparity has the potential to reveal a more realistic view of binocular system functioning under normal viewing conditions than other systems of analysis, the approaches diverge in some very important ways, particularly in the understanding of the development of fixation disparity and its management. Whereas the philosophy underlying testing and management of the motor-based approach will be familiar to most clinicians in the United States, the sensory approach offers a very different perspective. It views the development of fixation disparity as a shift of correspondence within Panum's area. In effect, this may be thought of as the oxymoron "a normal, anomalous correspondence"; that is, a shift of correspondence occurring in nonstrabismic patients. Management in these cases is based on accurate prism prescription to re-establish bifoveal fusion.

Asthenopia↗

Computer vision syndrome: a review.

As computers become part of our everyday life, more and more people are experiencing a variety of ocular symptoms related to computer use. These include eyestrain, tired eyes, irritation, redness, blurred vision, and double vision, collectively referred to as computer vision syndrome. This article describes both the characteristics and treatment modalities that are available at this time. Computer vision syndrome symptoms may be the cause of ocular (ocular-surface abnormalities or accommodative spasms) and/or extraocular (ergonomic) etiologies. However, the major contributor to computer vision syndrome symptoms by far appears to be dry eye. The visual effects of various display characteristics such as lighting, glare, display quality, refresh rates, and radiation are also discussed. Treatment requires a multidirectional approach combining ocular therapy with adjustment of the workstation. Proper lighting, anti-glare filters, ergonomic positioning of computer monitor and regular work breaks may help improve visual comfort. Lubricating eye drops and special computer glasses help relieve ocular surface-related symptoms. More work needs to be done to specifically define the processes that cause computer vision syndrome and to develop and improve effective treatments that successfully address these causes.

Asthenopia↗

Visual protective sheet can increase blink rate while playing a hand-held video game.

PURPOSE: To evaluate the effectiveness of a protective sheet in reducing eye strain caused by unnecessary light reflection on portable liquid crystal display panels while playing Game Boy (Nintendo, Kyoto, Japan). DESIGN: Nonrandomized clinical trial. METHODS: The blink rates of 24 normal volunteers were measured under relaxed conditions while viewing a portable liquid crystal display panel and playing Game Boy with and without the protective sheet of polyethylene terephthalate with antiglare coating for a total of 10 minutes each. RESULTS: The results showed a dramatic increase (from 5.6 +/- 3 to 9.1 +/- 4.9 [P <.0001]) in blinks/minute with use of the protective sheet. CONCLUSION: The protective sheet has shown the possibility of increasing the blink rate by making the screen easier to see.

Adult↗

Polarized task lighting to reduce reflective glare in open-plan office cubicles.

This ergonomic study deals with the common situation where a glossy document is placed between a viewer and an under-shelf task light source in a common open-plan office cubicle workstation. With a task lamp in front, when looking at a document a viewer sees two images, the document itself and specular glare, which is the reflected image of the light source. Specular glare or veiling reflection causes eye discomfort, makes it difficult to read a document and has been thought to contribute to eyestrain. This paper analyzes the application of polarized lighting for this specific situation. The use of a linear polarized light source helps to minimize specular glare by darkening the reflected image of the light source on the document. The performance and predictive optimization of the use of polarized lighting in this situation is investigated according to female and male viewer height demographics. Theoretical predictions and light measurement analysis of specular glare reduction are compared with empirical results from testing on a panel of humans on semi-gloss finish and matte finish papers. This study shows that with the right alteration of a polarized light source position, specular glare may be significantly reduced, and correlations exist between the theory, empirical measurements and the human response to specular glare reduction.

Analysis of Variance↗

Industrial inspection performance depends on both viewing distance and oculomotor characteristics.

The influence of viewing distance and individual differences in the oculomotor resting states (dark vergence and dark focus) on both inspection performance and visual fatigue was investigated by asking 24 college students to perform a visual inspection task for 40 min twice, once with a 20 cm viewing distance and once with a 60 cm viewing distance. During the task participants visually searched enlarged images of contact lenses for six different types of defects. Lens images were presented at a constant visual angle (17.5 degrees) on a CRT. Inspection performance varied significantly across the two viewing distances: participants spent on average more than twice as much time inspecting individual lenses in the near condition (mean = 18.32 s lens(-1)) than in the far condition (mean = 7.25 s lens(-1)). Participants also reported greater visual fatigue in the near condition than in the far condition. At both viewing distances, participants who experienced relatively large inward shifts in dark vergence also tended to be slow inspectors. Neither inspection performance nor measures of fatigue were related to dark focus. These results support existing evidence against the use of near viewing distances and suggest that an oculomotor mechanism links inspection performance and visual fatigue to viewing distance.

Accommodation, Ocular↗

Dermatochalasis and blepharochalasis of the upper lids.

Dermatochalasis and blepharochalasis of the upper lids, in addition to producing a cosmetic defect, causes asthenopic symptoms. A blepharoplasty for dermatochalasis removes skin only. Blepharochalasis removes protruding fat, tightens the orbital septum, and, in addition, when indicated removes excess skin. The surgical techniques for these procedures are presented.

Asthenopia↗

Occupational health hazards to the ultrasonographer and their possible prevention.

Occupational health hazards in ultrasonography are becoming more prevalent as the field continues to grow. Eye strain, musculoskeletal pain or injury, carpal tunnel syndrome, repetitive strain injuries, stress, burnout, and other hazards have been addressed as concerns in other studies and surveys. These topics are discussed, as well as the possible preventive measures that may be used to maximize and maintain the ultrasonographer's well-being throughout his or her career.

Asthenopia↗

Effects of two eye drop products on computer users with subjective ocular discomfort.

BACKGROUND: An increasing number of people seek medical attention for symptoms of visual discomfort due to computer vision syndrome (CVS). We compared the efficacy and adverse event rates of a new eye lubricant, OptiZen (InnoZen, Inc., polysorbate 80 0.5%) and Visine Original (Pfizer Consumer Healthcare, tetrahydrozoline HCl 0.05%). METHODS: In this double-blind parallel arm trial, 50 healthy men and women, ages 18 to 65 years, with symptoms of CVS who use a video display terminal for a minimum of 4 hours per day were randomized to OptiZen (n = 25) or Visine Original (n= 25), 1 to 2 drops b.i.d. for 5 days. The primary end-points were ocular discomfort and adverse events. RESULTS: OptiZen and Visine Original had similar efficacy in alleviating symptoms of ocular discomfort (odds ratio of 1.23 [95% confidence interval, 0.63 to 2.42], P= 0.55). OptiZen and Visine Original were very similar with respect to odds ratios and 95% confidence interval (CI) for each of the measurement times (P= 0.72). Visine Original users reported a significantly higher incidence of temporary ocular stinging/burning immediately after drug instillation (28%, 7/25) than did OptiZen users (4%, 1/24) (P= 0.05). Patients using OptiZen were 89% less likely to have stinging/burning effects than those patients using Visine Original (95% CI: 0.01 to 0.95). DISCUSSION: OptiZen and Visine Original are effective at alleviating ocular discomfort associated with prolonged computer use. Adverse event findings suggest that OptiZen causes less ocular discomfort on instillation, potentially attributable to its milder ingredient profile.

Adolescent↗