• Title/Summary/Keyword: 크로스실린더

Search Result 13, Processing Time 0.021 seconds

A Study on the Accommodative Astigmatism of Near Vision (근거리 주시 시 조절성 난시에 대한 연구)

  • Lee, Hark-Jun
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.16 no.3
    • /
    • pp.327-331
    • /
    • 2011
  • Purpose: The purpose of this study was an accurate grasp of the astigmatic change due to eyes accommodation on near vision and suggested problems occurring accommodative astigmatism using near glasses. Methods: 154 subjects(308eyes) from 20 to 40 years selected for this study who had many opportunity of near vision. First, far vision corrective refraction measured using the phoropter, and then both eyes opened simultaneously for maintaining the function of binocular put away dot chart 40 cm. One eye was fogging and the other eye measured near vision astigmatism axis and degrees astigmatism using cross cylinder, and then compared with far astigmatism. Results: Increased degree of astigmatism persons on near vision more than decreased or did not changed degree of astigmatism persons, which could affect visual acuity more than 0.75 diopters in 30 eyes with an increase of 9.7% of total subjects. Direct astigmatism and oblique astigmatism were increased on near vision. Astigmatic axes were rotated base in direction on both eyes and 66.9% of subjects were more than ${\pm}$5$^{\circ}$ rotation. Due to the rotation axis of astigmatism, residual astigmatism is expected to occur and expect to adversely affect the eyes. Conclusions: Long-term using the glasses without correction of increased astigmatic and rotated axis on near vision should occur new residual astigmatism and increase the asthenopia also. Considered to be taken astigmatic change on near vision during near refraction examination.

A Study for Exact Spherical Diopter by Cross Cylinder Lens and Red·Green Card Method (크로스 실린더법과 적·녹검사를 이용한 정밀구면 굴절력에 관한 고찰)

  • Yoon, Kyounghan
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.4 no.2
    • /
    • pp.39-43
    • /
    • 1999
  • In this study, It obtained results that the exact spherical diopter to practice test by using Cross cyliner lens and Red Green Card method. In the test used to the 1750 eyes of middle and high school students. The results was as follows ; 1. Using Cross cylinder lens method, I tested a exact spherical diopter after accommodation. At -0.25 Dptr the ratio of spherical Dptr error limits were measured as 58% and at -0.75 Dptr they were oppeared as 1%, at -1.00 Dptr they are not measured. In this method, the error limits of exact spherical Dptr was 91% from 0 Dptr to -0.25 Dptr. 2. Using Red Green Card method, they were measured as 45% at -0.25 Dptr. and measured as 20% at -0.50 Dptr. From the result of these test, Cross cylinder lens method was a better detailed method than Red Green Card method.

  • PDF

A Clinical Study on Relation among Accommodative Amplitude, Response, and Facility in young adults (청.장년층에서 조절력 및 조절반응과 조절용이의 상관관계에 관한 임상적 연구)

  • Shim, Hyun-Seog;Joo, Seok-Hee;Leem, Hyun Sung
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.14 no.1
    • /
    • pp.115-119
    • /
    • 2009
  • Purpose: This study has been conducted to know the relation among accommodative amplitude, response, and facility. Methods: 61 subjects were students without any ocular diseases and presbyopia in a university, Korea. After far distance visual acuity was fully corrected, the amplitude was measured through Push-Up test, the response was measured through Jackson crossed cylinder ${\pm}$0.25D and the facility was measured through +2.00/ -2.00D flipper. Results: The relation among accommodative facility, response and amplitude had not indicate significant level in monocular and binocular. In binocular, 12 eyes (19.6%) had a difference in amplitude, 9 eyes (14.7%) had a difference in response, 2 eyes (3.2%) had a difference in facility from norm which would be expected from their age. 4 eyes (6.5%) had difference in both amplitude and response. 2 eye (3.2%) had difference in both amplitude and facility. In all three of the amplitude, response, facility had not difference. Conclusions: The evaluation of accommodative functions and a patients accommodative dysfunction is examined all facets of amplitude, response, and facility.

  • PDF