Refractometry process and device for measuring the degree of ametropia, and especially the degree of astigmatism, of the eye
US4619505A · kind A · utility
2Cited by
1References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 16, 1984 |
| Grant date | Oct 28, 1986 |
| Priority date | — |
| Expiry date | May 16, 2004 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/1035
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The invention concerns a process and device for measuring the degree of ametropia of an eye. The rays of a luminous source passes through a focussing lens and a test lens in order to create an image on the retina. The rays issuing from the source or from the image pass through a black optical slit and are reflected by at least one reflecting surface defined in a revolving screen driven in rotation by a motor. Application to refractometric instruments for measuring the degree of ametropia of the eye.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.