TY - JOUR PY - 2000// TI - Prescription safety eyewear: impact studies of lens and frame failure JO - Optometry: Journal of the American Optometric Association A1 - Vinger, Paul F. A1 - Woods, T. A. SP - 91 EP - 103 VL - 71 IS - 2 N2 - OBJECTIVES: To determine if a plano lens could be the test lens for all prescription (Rx) lenses and to investigate why Rx lenses pop out of safety eyewear. DESIGN: Plano and Rx polycarbonate lenses (n = 641) with varying thickness and edge geometry, mounted on steel lens holders, and Rx safety eyewear (n = 128) placed on headforms were impacted with test objects of varying diameter and hardness. Impacts were studied with 500 to 2,000 frames-per-second motion analysis. RESULTS: Plano lenses were at least, or more, prone to failure (dislodgment, perforation, shatter, or crack) than -3.00 or +3.00 lenses of the same minimum thickness. More than 40% of safety frames with removable lenses broke or had lenses pop out when impacted with energies expected in industry and sports. CONCLUSIONS: Plano lenses can be used as the test lenses for all Rx lenses made of the same material with the same minimal thickness. The ANSI Z87.1-1989 industrial standard for Rx eyewear is inadequate for sports or other activities with high-impact potential. The best lens-retention system has, as a component, a frame with a bevel perpendicular to a frontal impact force.

Language: en

LA - en SN - 1529-1839 UR - http://dx.doi.org/ ID - ref1 ER -