Method for the manufacture of contact lenses

• US 5,114,628 A
• Filed: 01/23/1991
• Issued: 05/19/1992
• Est. Priority Date: 01/24/1990
• Status: Expired due to Term

• Current Assignee: CIBA Vision Corporation (Bayer AG)
• Original Assignee: Ciba-Geigy Corporation (Novartis Ag)
• Inventors: Vaas, Eberhard, Hagmann, Peter, Krieg, Gunther, Hofer, Peter
• Primary Examiner(s): Lowe, James
• Application Number:
  US07/644,355
• Time in Patent Office: 482 Days
• Field of Search: 264/1.1, 264/2.5, 264/40.1, 264/1.4, 156/58, 156/59, 156/626, 156/643, 51/104 LG, 51/284 R
• US Class Current: 264/1.37
• CPC Class Codes: B23K 26/08 Devices involving relative movement between laser beam and workpiece
• CPC Class Codes: B23K 26/082 Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head
• CPC Class Codes: B24B 13/046 using a pointed tool or scraper-like tool B24B13/015 and B24B13/065 take precedence
• CPC Class Codes: B24B 13/06 grinding of lenses, the tool or work being controlled by information-carrying means, e.g. patterns, punched tapes, magnetic tapes
• CPC Class Codes: B29D 11/00461 Adjusting the refractive index, e.g. after implanting
• CPC Class Codes: B29D 11/00932 Combined cutting and grinding thereof
• CPC Class Codes: G02C 7/04 Contact lenses for the eyes disinfection or sterilisation of contact lenses A61L12/00

Abstract

A method for the manufacture of contact lenses, especially individually fitted contact lenses, and a contact lens production system therefor is described, wherein the topography of the surface of the eye is measured three-dimensionally, the geometry of the rear face of the lens is determined so as to fit the topography measured, the optical effect of a lachrymal lens which is formed between the rear face of the lens and the surface of the eye is determined, the geometry of the front face of the lens is determined taking into account the optical effect of the lachrymal lens and the sight correction to be achieved, and the data so obtained for the lens geometry of the front and rear faces of the lens are stored and transferred to a control arrangement for the manufacture of the lens in a machine tool.

Claims

1. A method for the manufacture of contact lenses, wherein

the topography of the surface of the eye is measured three-dimensionally;

the geometry of the rear face of the lens is determined so as to fit the measured topography;

the optical effect of a lachrymal lens which is formed between the rear face of the lens and the surface of the eye is determined;

the geometry of the front face of the lens is determined taking into account the optical effect of the lachrymal lens and the sight correction to be achieved by the contact lens;

the data for the lens geometry of the front and the rear faces of the lens are stored; and

the particular contact lens concerned is produced in accordance with the stored lens geometry data.

2. A method according to claim 1, wherein lens production is effected by removing material from a lens blank, and the material-removing tool is controlled by the stored geometry data.

3. A method according to claim 2, wherein a cutting tool is used as the material-removing tool.

4. A method according to claim 2, wherein a laser beam is used as the material-removing tool.

5. A method according to claim 1, wherein the contact lens is manufactured by casting and the geometry of the moulding faces of the mould is shaped in accordance with the stored geometry data of the lens.

6. A method according to claim 5, wherein the shaping tools for the manufacture of the moulding faces of the mould or the stamping die are shaped in accordance with the stored geometry data of the lens.

7. A method according to claim 1, wherein the contact lens is manufactured in accordance with the thermoforming process using a stamping die, the moulding stamp faces of which have been formed in accordance with the stored geometry data of the contact lens.

8. A method according to claim 7, wherein the shaping tools for the manufacture of the moulding faces of the mould or the stamping die are shaped in accordance with the stored geometry data of the lens.

9. A method according to claim 1, wherein the geometry of the rear face of the lens is determined additionally in accordance with statistical data obtained during fitting checks.

10. The method according to claim 1, wherein the geometry of the rear face of the contact lens, the optical effect of the lachrymal lens and the geometry of the front face of the contact lens are determined by computer.