Answers are grounded in this paper and cite their sources.
A new testing method measures fracture resistance in ophthalmic lenses, suggesting improved accuracy and speed.
The Drop Ball Test (DBT) has some distinct disadvantages both as a standard measurement for ophthalmic lens fracture resistance and as a research tool. The Static Test (ST) was devised to allow a load and energy analysis of the DBT and enable more rapid and accurate testing of large ophthalmic lens samples. It was found that over 50% of the energy generated in the DBT is absorbed by the lens mount instead of the test lens. This means that the standard DBT height of 50 inches is more an indication of DBT components than lens fracture resistance. Static testing of non‐tempered, beat tempered and chemically tempered lenses correlated well with former DBT studies. The ST, however, allowed lens fracture resistance to be represented in pounds‐load, a value better understood practically and mathematically.
No takes yet. Share an insight, caveat, or question.
A. Lee Scaief (1975) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: