CPC G01N 1/30 (2013.01) [G01N 1/04 (2013.01); G01N 21/77 (2013.01); G02B 1/043 (2013.01); G01N 2001/302 (2013.01); G01N 2021/7786 (2013.01)] | 6 Claims |
1. A method for determining the thickness of coatings on the surfaces of contact lenses, comprising the steps of:
(a) obtaining a coated contact lens in fully hydrated state, wherein the coated contact lens comprises a lens body and a coating thereon, wherein the lens body comprises a non-silicone hydrogel material or a silicone hydrogel material, wherein the coating comprises a coating material having negatively-charged groups;
(b) selectively staining the coating over the lens body of the coated contact lens by immersing the coated contact lens in an aqueous solution of a fluorescently-labeled polycationic polymer for a time period of about 12 hours or less, wherein the aqueous solution comprises buffering agents in an amount for having a pH of from about 6.5 to about 8.0;
(c) orthogonally cutting the selectively-stained coated contact lens; and
(d) determining the thickness of the coating on the coated contact lens.
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