Yestin Johnson

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Lens retention in metal and zyl safety frames was tested using both a high mass (500 g), low velocity impact (HM-LV), and a low mass (1.04 g), high velocity impact (LM-HV) for plano polycarbonate lenses of various thicknesses. The results showed that the metal safety frames retained lenses better than the zyl (p < 0.01) after a HM-LV impact. For the LM-HV(More)
The use of the internet, and in particular web browsing, offers many potential advantages for educational institutions as students have access to a wide range of information previously not available. However, there are potential negative effects due to factors such as time-wasting and asocial behaviour. In this study, we conducted an empirical investigation(More)
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