Heterogeneous visual acuity chart and visual acuity testing method and device
US11445905B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Jun 22, 2020 |
| Grant date | Sep 20, 2022 |
| Priority date | — |
| Expiry date | Jun 22, 2040 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/0041
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A heterogeneous visual acuity chart and a visual acuity testing method and device are provided. The heterogeneous visual acuity chart is a size illusion chart composed of a heterogeneous reference zone and at least two types of optotypes of different sizes, where the heterogeneous reference zone is used to cause incorrect identification on the different types of optotypes of different sizes. The visual acuity testing method and device determine whether a visual acuity of a subject is true based on a difference between visual acuities tested with the heterogeneous visual acuity chart and a standard logarithmic visual acuity chart. The visual acuity chart is a size illusion chart composed of optotypes of different sizes and a perspective, which causes an illusion on a visual depth to interfere with the identification of the optotypes of different sizes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.