@article{ref1,
title="Material and thickness: the important factors in the impact resistance of spectacle lenses",
journal="Canadian journal of ophthalmology",
year="1977",
author="Christianson, M. D. and Parker, J. A. and Arndt, J.",
volume="12",
number="4",
pages="300-303",
abstract="The identify the population at risk of permanent visual impairment from injuries associated with spectacles, we analysed 446 cases of penetrating ocular injury occurring over a ten year period. Sixteen injuries (3.6%) were due to spectacles; 40% of these were adult male amateur athletes. We used the drop-ball test to determine the important factors in the resistance to impact of 177 used spectacle lenses (29 plastic C39, 40 heat-tempered glass, 108 non-tempered glass). We found that material and thickness were the most important. The plastic lenses were the most impact resistant and non-tempered glass lenses the least, with heat-tempered glass lenses falling between. Plastic lenses of adequate centre thickness mounted in plastic frames are recommended for all children and all adults involved in athletics.<p /><p>Language: en</p>",
language="en",
issn="0008-4182",
doi="",
url="http://dx.doi.org/"
}