Claims
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1. A method of measuring centration of a lens, the method comprising:
){LU>MW{& placing the lens on a platen, wherein the lens comprises a first major surface and a second major surface, wherein the first major surface is rotationally symmetrical about a first axis, and further wherein the first major surface comprises a first lens centration mark located at the intersection of the first major surface and the first axis, wherein placing the lens on the platen comprises placing the lens on the platen such that the first lens centration mark is aligned with a rotation axis of the platen;
DHg)]FQ/ leveling the lens relative to a plane of rotation that is orthogonal to the rotation axis of the platen;
A]laS7Q rotating the lens about the rotation axis of the platen; and
{SF'YbY observing the lens during or alter rotation to assess centration of the first major surface of the lens.
e'yw8U5E/ 2. The method of claim 1, wherein assessing centration of the first major surface of the lens comprises:
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measuring a maximum distance from a reference point to an outer edge of the lens as the lens rotates;
}Ug$d>\ measuring a minimum distance from the reference point to the outer edge of the lens as the platen and lens rotate; and
Up1n0 comparing the minimum distance and the maximum distance.