Verification of the ball lens of trial lens set, adjust the prism display of the instrument to the state of polar coordinates.

1. Vertex power detection

Place the inspected lens on the supporting seat of the instrument and move the lens gently to make the prism display value 0 or the minimum. At this time, the reading of the instrument is the vertex power of the inspected lens.

2. Verification of optical center displacement

The optical center displacement is expressed by the prism degree of the geometric center of the lens ring. The detection of the optical center is to place the geometric center of the lens at the geometric center of the instrument support base, and move the lens so that the prism degree in the vertical direction is 0 or the smallest, and the prism degree in the horizontal direction is the largest. Then the instrument measures the horizontal direction The prism degree is the displacement of the optical center of the inspected lens.