Visual equipment for checking close vision working distance
US6325508A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1999 |
| Grant date | Dec 4, 2001 |
| Priority date | — |
| Expiry date | Dec 23, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C11/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
There is provided a spectacle frame 1, having a least one corrective lens the characteristics of which do not vary over time and having telemetry means 5 which set off an alarm 9, 10 when the distance measured by the telemetry means is less than a predetermined preference distance. This reference distance can for example be set at between 20 and 50 cm depending on the spectacle wearer. A kit is also provided comprising a frame, telemetry means and an alarm. The spectacle frame can be prescribed for slowing down the evolution of acquired myopia in children who are starting to acquire myopia; here, the spectacle frame is provided with progressive multifocal lenses. The telemetry means and alarm incite the child to respect a sufficient working distance for close vision.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.