Delensing of ophthalmic lenses using gas
View Patent ↗Contact lens delensing methods are described, and the present delensing methods include using a gas to facilitate separation of a polymerized contact lens product from a contact lens mold member. The contact lens mold member is compressed to deform a portion of the mold member, and gas, such as air, is directed toward the polymerized contact lens product in contact with the portion. The contact lens mold member can be compressed as the mold member, and lens product, rotate. A vacuum device can be used to separate the polymerized contact lens product from the contact lens mold member after compressing the portion of the mold member and directing the gas towards the mold member. Delensing systems used to practice the present methods are also described.
1. A method of delensing a polymerized contact lens product from a contact lens mold member, comprising:
demolding a contact lens mold to separate a first contact lens mold member and a second contact lens mold member from each other, such that a polymerized contact lens product remains attached to or in contact with one of the first contact lens mold member or the second contact lens mold member, the first contact lens mold member having a concave surface defining an anterior lens surface and the second contact lens mold member having a convex surface defining a posterior lens surface;
compressing a portion of the one of the first contact lens mold member or the second contact lens mold member having the polymerized contact lens product attached to or in contact therewith; and
directing a gas toward the polymerized contact lens product to facilitate separation of the polymerized contact lens product from the portion of the one of the first contact lens mold member or the second contact lens mold member;
wherein the compressing step and directing step occur simultaneously, and the polymerized contact lens product is a pre-extracted silicone hydrogel contact lens.
2. The method of claim 1 , wherein the one of the first contact lens mold member and the second contact lens mold member comprises a polyolefin resin material.
3. The method of claim 1 , wherein the portion of the one of the first contact lens mold member or the second contact lens mold member is the second contact lens mold member having a convex surface forming a posterior lens surface, and the portion is compressed below the polymerized contact lens product.
4. The method of claim 1 , wherein the gas is air.
5. The method of claim 1 , wherein the compressing comprises compressing substantially opposing regions of the portion of the one of the first contact lens mold member or the second contact lens mold member.
6. The method of claim 1 , wherein the directing comprises directing the gas toward substantially opposing regions of the portion of the one of the first contact lens mold member or the second contact lens mold member.
7. The method of claim 1 , further comprising placing the one of the first contact lens mold member or the second contact lens mold member on a rotatable chuck prior to compressing the portion of the one of the first contact lens mold member or the second contact lens mold member or directing gas toward the polymerized contact lens product.
8. The method of claim 1 , further comprising separating the polymerized contact lens product from the portion of the one of the first contact lens mold member or the second contact lens mold member using a vacuum device.
9. The method of claim 8 , further comprising placing the separated polymerized contact lens product on a lens carrier.
10. The method of claim 1 , further comprising rotating the one of the first contact lens mold member or the second contact lens mold member prior to compressing the portion thereof or directing gas toward the polymerized contact lens product, and separating the polymerized contact lens product from the portion of the one of the first contact lens mold member or the second contact lens mold member using a rotating vacuum device which rotates at the same rate and direction as the rotating one of the first contact lens mold member or the second contact lens mold member.
11. The method of claim 1 which is effective in separating the polymerized contact lens product from the one of the first contact lens mold member or the second mold member without adversely affecting the optical properties of a hydrated contact lens obtained from the polymerized contact lens product.