Title:
REFRACTION TEST CARD AND TEST METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2022/156826
Kind Code:
A1
Abstract:
A refraction test card (30, 40, 50) and a test method therefor. The test card (30, 40, 50) involves an optotype (32, 42, 52) in a black background (31, 41, 51). The center position of the optotype (32, 42, 52) comprises a partition unit (33, 43, 53), and the partition unit (33, 43, 53) visually separates the optotype (32, 42, 52). The test method comprises: according to the clarity of contrast between an optotype (32, 42, 52) and a black background (31, 41, 51) of an astigmatism test card, determining whether a subject has astigmatism; if it is determined that the subject has astigmatism, determining an astigmatism axis direction; according to the clarity of contrast between an optotype (32, 42, 52) and a black background (31, 41, 51) of a spherical degree test card, determining whether the subject has near-/far-sightedness; and testing and calculating the spherical degree and the astigmatism degree of the subject. In the present invention, a simple optometry tool and a method therefor are provided to determine: whether a subject has ametropia; the type of ametropia; and the amount of ametropia.
Inventors:
LAU CHUN HO (CN)
LAU CHUN PUT (CN)
LAU CHUN PUT (CN)
Application Number:
PCT/CN2022/079250
Publication Date:
July 28, 2022
Filing Date:
March 04, 2022
Export Citation:
Assignee:
LAU CHUN HO (CN)
LAU CHUN PUT (CN)
LAU CHUN PUT (CN)
International Classes:
A61B3/028; A61B3/032; A61B3/036
Foreign References:
| CN214965399U | 2021-12-03 | |||
| JP2007268170A | 2007-10-18 | |||
| CN105764405A | 2016-07-13 | |||
| US20200397279A1 | 2020-12-24 | |||
| JPH06304139A | 1994-11-01 | |||
| CN111265182A | 2020-06-12 | |||
| CN1438852A | 2003-08-27 |
Attorney, Agent or Firm:
BEIJING GAOWO LAW FIRM (CN)
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