Equipment accessory configuration:

1. One sand drop testing machine

2. 1 pack of artificial diamond sand

3. 1 copy of product manual

Preparation before testing:

Lens requirements: The curvature radius of the front surface of the tested lens should be greater than 75mm, and the absolute value of the top power should not exceed 0.50D for uncut lenses.

Lens cleaning: Before testing, the surface of the lens needs to be cleaned thoroughly, removing any residue, and placed under standard environmental conditions for about 2 hours.

Test position marking: The haze value test position should be marked in four directions (0 °, 90 °, 180 °, 270 °) in the central area of the lens to ensure consistency of the test position.

Preparation of testing materials and tools:

Steel Velvet: 000 # steel velvet should be used, and its friction surface should be flat, orderly arranged, and not oxidized. The new steel wool needs to be run in first (with a load of 750g, rubbed back and forth 200 times with hardened resin lenses) to eliminate burrs and oxidation effects.

Rubber head: diameter ranging from 6.5mm to 7.0mm.

Defatted gauze: It needs to be folded into 12 layers and wrapped around the rubber head, and fixed on the clamp of the friction tool.

Test steps:

Initial haze measurement: Place the lens on the haze meter, measure the initial haze values in the four directions of the central area of the lens without friction, and take the arithmetic mean.

Wear resistance test:

Fix the convex surface of the lens upwards on the friction tester, with the center coinciding with the center of the pendulum.

Add a weight with a total load of 750g ± 15g to the upper end of the mold.

Start the friction tester and rub the lens back and forth 1000 times.

Final haze measurement: After the test is completed, measure the haze value in the center area of the lens again and compare it with the initial value to evaluate the degree of wear.