PERSONAL EYE PROTECTORS: PERFORMANCE REQUIREMENTS AND TESTING

The performance requirements for personal eye protectors are identified and discussed under the two headings of (a) the factors that influence wearer acceptance and (b) strength. The relative importance of these two groups of factors is shown to vary with the application. Their relevance is therefore discussed in the two differing but complementary contexts of (i) intermittent and (ii) constant, day-long use. This section suggests that, for day-long use, protection should be afforded by properly fitted, optically correct spectacles glazed with lenses of allyl resin or toughened glass. This is supplemented by the additional intermittent use of high-impact protectors for special operations. The bulk of the paper is devoted to an examination of the ways in which eye protector strengths are measured. It is emphasized that testing methods should simulate real-life hazards. Clinically observed eye injuries consist of blunt trauma from large missiles and penetrating injuries from small ones. These can be conveniently simulated in the laboratory by dynamic tests using (a) a 25 m.m. (one inch) steel ball in a drop tower system and (b) a 3 m.m. (118 inch) steel ball in a ballistic system. These tests are proposed. Sample size, missile type and test procedures are also discussed in detail.