Purpose: To determine the prevalence of symptoms of computer vision syndrome and to identify its associated factors. The secondary objective was to assess knowledge and practices related to preventing computer vision syndrome symptoms. Methods: The data for this cross-sectional study were collected through a self-administered questionnaire distributed to 713 female undergraduates studying business and medicine in Saudi Arabia. The questionnaire included computer vision syndrome validated symptoms and factors associated with computer vision syndrome development. Results: The most common symptom due to prolonged computer use was neck or shoulder pain, reported by 82.2% of the subjects. Overall, 66.5% of the subjects suffered from headache and 51.5% from dry eyes, in mild, moderate, or severe form. Business students were 1.6 times as likely as medical students to suffer from computer vision syndrome (odds ratio = 1.65; 95% confidence interval: 1.22, 2.24). The use of electronic devices for more than 5 h (odds ratio = 1.52; 95% confidence interval: 1.07, 2.16) was also associated with experiencing computer vision syndrome symptoms. Regarding computer vision syndrome prevention, factors such as hours of use, screen distance, screen brightness, and room illumination showed statistically significant difference between the two groups (p < 0.0001). Conclusion: The prevalence of computer vision syndrome symptoms was significantly higher among business students, who reported lower awareness and poor practice measures of computer use recommendations. Relevant awareness campaigns focusing on the appropriate use of computers are highly recommended.

We present a Raman mapping study of monolayer graphene G and 2D bands, after integration on silicon strip-waveguide-based micro-ring resonators (MRRs) to characterize the effects of the graphene transfer processes on its structural and optoelectronic properties. Analysis of the Raman G and 2D peak positions and relative intensities reveal that the graphene is electrically intrinsic where it is suspended over the MRR but is moderately hole-doped where it sits on top of the waveguide structure. This is suggestive of Fermi level ‘pinning’ at the graphene-silicon heterogeneous interface, and we estimate that the Fermi level shifts down by approximately 0.2 eV from its intrinsic value, with a corresponding peak hole concentration of ~ 3 × 1012 cm−2. We attribute variations in observed G peak asymmetry to a combination of a ‘stiffening’ of the E 2g optical phonon where the graphene is supported by the underlying MRR waveguide structure, as a result of this increased hole concentration, and a lowering of the degeneracy of the same mode as a result of localized out-of-plane ‘wrinkling’ (curvature effect), where the graphene is suspended. Examination of graphene integrated with two different MRR devices, one with radii of curvature r = 10 μm and the other with r = 20 μm, indicates that the device geometry has no measureable effect on the level of doping.

Abstract:We examine the near-IR light-matter interaction for graphene integrated cavity ring resonators based on silicon-on-insulator (SOI) racetrack waveguides. Fitting of the cavity resonances from quasi-TE mode transmission spectra reveal the real part of the effective refractive index for graphene, n eff = 2.23 ± 0.02 and linear absorption coefficient, α gTE = 0.11 ± 0.01dBμm −1 . The evanescent nature of the guided mode coupling to graphene at resonance depends strongly on the height of the graphene above the cavity, which places limits on the cavity length for optical sensing applications. ©2014 Optical Society of America