Citation

Corzine JC, Greer RB, Bruess RD, Lee GK, Scaief AL. Optom. Vis. Sci. 1996; 73(1): 8-15.

Affiliation

School of Optometry, University of California, Berkeley, USA.

Copyright

(Copyright © 1996, Lippincott Williams and Wilkins)

DOI

unavailable

PMID

8867676

Abstract

BACKGROUND: Scratch-resistant (SR) and anti-reflective (AR) coatings are commonly applied to plastic ophthalmic lenses. Fracture resistance is greatly affected by surface characteristics, and coatings may have a weakening effect. Static load testing is an efficient, quantifiable alternative to the drop ball test and has been suggested as useful for comparing lenses of a given material. METHODS: An Instron static load tester was used to test the fracture resistance of 140 CR-39 lenses divided into 4 groups: uncoated, prepared for AR coating but not actually coated, AR coated, and factory SR coated. RESULTS: Compared to the control uncoated group, AR coating reduced the required fracture energy by 63% and SR coating by 57%. Preparation for AR coating had no significant effect. CONCLUSIONS: These results are at least qualitatively consistent with drop ball testing and have significant implications as new plastic materials are developed, made thinner, and variously coated.

Language: en