Materials for occupational eye protectors

Abstract

The selection of lens materials for non‐prescription personal protective equipment has been a relatively simple process and has its origins in many studies around the 1970s. The viable materials available at that time were tempered glass, hard resin (n = 1.50) and polycarbonate. The modern spectacle non‐prescription eye protector of choice is inevitably hard coated polycarbonate, which has exemplary impact resistant properties. In the prescription lens area, there is a bewildering array of materials of various refractive indices with a variety of coatings. The selection of an ophthalmic lens has optical and cosmetic considerations ahead of impact resistance. In complying with the Australian/New Zealand standard on prescription eye protection, adequate impact resistance must rate as the foremost requirement, with optical and cosmetic considerations as important but lesser considerations. In this review, the evidence on impact resistance of the available materials is presented, the standards set for testing impact resistance are detailed and some guidance is provided for the selection of prescription eye protection materials.

Key words:

• eye injuries
• eye protection
• occupational safety
• ophthalmic materials

ACKNOWLEDGEMENTS

I acknowledge the valued assistance, however inadvertent and unintentional, of the members of Standards Australia/Standards New Zealand committees SF‐006 Eye and face protection, CS‐053 Sunglasses and fashion spectacles and CS‐084 Eye protection for racquet sports and the International Standardization Organization committee TC95/SC6 Eye and face protection. The members of the eye and face protection and sunglass industries have always been most helpful. Glyn Walsh of Glasgow Caledonian University provided valuable advice on the draft manuscript. Finally, my thanks to the staff of the Optics & Radiometry Laboratory who are the ones who have the responsibility for the actual hands‐on testing of eye and face protection and sunglasses.