Impact resistance is an essential criterion for U.S. bound glasses and/or lenses.
The drop ball test must follow the requirements:
1. The impact test will consist of a 5/8 inch steel ball weighing approximately 0.56 ounces
2. The ball should be dropped from a height of 50 inches from the horizontal upper surface of the lens
3. The geometric center of the lens should be struck by the ball within a 5/8 inch diameter circle
4. There cannot be anything restricting the fall of the ball
5. A tube may be used to guide the ball to the lens; the ball may be dropped through a tube extending to within approximately 4 inches of the lens
We choose the market normal lens and Yuzhou Optics PR film lens for testing.