True or False: Polycarbonate, high-index plastic, and CR-39 lenses do not have to be routinely tested in the lab by the drop-ball testing.

• A. True
• B. False
• C. Not sure
• D. Sometimes

Answer: (A)

Impact resistance testing with a drop-ball procedure is used to ensure lenses won’t crack or shatter on impact. Polycarbonate, high-index plastics, and CR-39 are standard ophthalmic lens materials with well-established performance and certified compliance with impact-resistance standards. Because their resistance to impact is already defined by manufacturers and safety standards, routine drop-ball testing for every lot isn’t typically required in normal production. Labs and clinicians rely on those material specifications and certifications to confirm safety. Testing would come into play if a safety requirement applies or if there’s concern about a particular batch.