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In this section: Guidance Documents (Medical Devices and Radiation-Emitting Products)

Impact-Resistant Lenses: Q&A -- Attachment B: Photographs of Drop Ball Test Unit - (impact tester)

Figure 1. In the drop ball impact test, a 5/8-inch steel ball is dropped onto the lens. A notice on the illustration states that safety glasses are required.

Figure 2. This figure illustrates that the ball may be guided but not restricted in its fall by being dropped through a tube extending to within approximately 4 inches of the lens.

Figure 3. The figure shows that the drop ball impact test shall be conducted with the lens supported by a tube (1-inch inside diameter, 11/4-inch outside diameter, and approximately 1-inch high) affixed to a rigid iron or steel base plate.