Impact Vulnerability of Scratched Glass Lenses.

摘要

Ophthalmic glass lenses of dress thickness were diamond scribed on their convex surfaces after heat or chemical tempering to a significant penetration of their compression layer. Nontempered lenses were similarly scratched. All were subjected to dropball impacts to examine whether the damaged tempered lenses would be more vulnerable to breakage than the scribed lenses that were not under internal stress. The results showed that the nontempered lenses had less impact resistance than the tempered. No significant difference in impact resistance was seen between the chemical-and heat-tempered groups. (Author)