Method and apparatus for simultaneously measuring the length and refractive error of an eye
US5975699A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 29, 1998 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Apr 29, 2018 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/1005
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Embodiments of the present invention are method and apparatus for simultaneously measuring the length and refractive error of an eye, preferably in a non-contact mode. In particular, an embodiment of the present invention is an apparatus which measures length and refractive error of an eye which includes: (a) a source of short coherence radiation which couples radiation into a Michelson interferometer, the arms of the Michelson interferometer having a predetermined optical pathlength difference; (b) an injector which couples radiation output from the interferometer into the eye; and (c) a relay system which couples radiation output from the eye to a spectrometer; wherein the spectrometer measures displacement of radiation to measure the refractive error and the spectrometer measures density of fringes to measure the length.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.