Effects of wink glass on blink rate, nibut and ocular surface symptoms during visual display unit use.

PURPOSE/AIM: Wink glass (WG), an invention to stimulate blinking at interval of 5 s was designed to reduce dry eye symptoms during visual display unit (VDU) use. The objective of this study is to investigate the effect of WG on visual functions that include blink rate, ocular surface symptoms (OSS) and tear stability during VDU use. MATERIALS AND METHODS: A total of 26 young and asymptomatic subjects were instructed to read articles in Malay language with a computer for 20 min with WG whereby their blink rate, pre- and post-task tear break-up time, and OSS were recorded. The results were compared to another reading session of the subjects wearing a transparent plastic sheet as a control. RESULTS: Non-invasive tear break-up time was reduced after reading session with transparent plastic sheet (pre-task = 5.97 s, post-task = 5.14 s, z = -2.426, p = 0.015, Wilcoxon), but remained stable (pre-task = 5.62 s, post-task = 5.35 s, z = -0.67, p = 0.501) during the reading session with WG. The blink rate recorded during reading session with plastic sheet was 9 blinks/min (median) and this increased to 15 blinks/min (z = -3.315, p = 0.001) with WG. The reading task caused OSS (maximum scores = 20) with median score of 1 (0-8) reduced to median score of 0 (0-3) after wearing WG (z = -2.417, p = 0.016). CONCLUSION: WG was found to increase post-task tear stability, increased blinking rate and reduced OSS during video display unit use among young and healthy adults. Although it may be considered as an option to improve dry eye symptoms among VDU users, further studies are warranted to establish its stability and its effect on subjects with dry eyes.

Near esophoria is associated with high myopia.

BACKGROUND: A retrospective study was undertaken to examine the hypothesis that esophoria is associated with higher amounts of myopia. METHODS: One hundred and forty-four subjects were selected from the files of optometry clinics at the Department of Optometry, National University of Malaysia, from the years 1995 to 1998 inclusive. These subjects were matched in terms of age group, sex, race and near phoria group. Near phorias were determined by Maddox wing technique and were classified into three groups: more than six prism dioptres exophoria, zero to six prism dioptres exophoria and any esophorias. RESULTS: One way analysis of variance revealed that there were significant differences in mean myopias between the three phoria groups (ANOVA, F(2,141) = 5.34, p < 0.01). Further analysis with the Student-Newman-Keuls test showed that the amount of myopia is significantly higher in the esophoric group than in the other two groups. CONCLUSIONS: The results support the hypothesis that near esophoria is associated with high myopia. This study suggests that near phoria might be an important factor in myopia development.