Fifty u sed and 373 new spectacle frames were tested for evidence of nickel release using dimethylglyoxime and ammonia. Nearly all the u sed frames (96%) tested positive. A lower proportion (24.5%) of new frames showed evidence of nickel leaching. It is suggested that this is evidence of non-conformance with the current British Standard () although all our suppliers...
An investigation was carried out into the thickness and standard of application of the plating and lacquer coatings applied to three metal spectacle frames. All conform to BS 6625 (1991) for plating thickness, but there was considerable variation in regularity and porosity.
British Standards specify a very small number of screw sizes as being acceptable for use in spectacle frames. We have measured the screw sizes of 50 frames, selected at random from the stock of Glasgow Caledonian University Clinic and have shown that very few of the screws used conform to these standards.
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