Contact lens
US5293186A · kind A · utility
42Cited by
14References
42Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 9, 1992 |
| Grant date | Mar 8, 1994 |
| Priority date | — |
| Expiry date | Jul 9, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N31/223
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
To improve its gas-permeability, a contact lens, which may be of any normal material, even a gas-impermeable material such as polymethylmethacrylate, is microperforated with 66000 holes distributed in equispaced sectors leaving unperforated the central (optically important) part and the outermost rim of the lens. With a smaller hole size, some one million holes can be accommodated. In a modification, some or all of the holes go only part way through the thickness of the contact lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.