• Title/Summary/Keyword: Astigmatic Components

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Clinical Study on Measurement Accuracy of Astigmatic Components (난시성분의 측정 정확도에 관한 임상적 연구)

  • Yoo, Jong-Sook;Sung, A-Young;Kim, Douk-Hoon
    • Journal of Korean Ophthalmic Optics Society
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    • v.11 no.1
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    • pp.63-69
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    • 2006
  • Clinical evaluation by Astigmatic Components of autorefractors was performed to examine validity and accuracy compared with subjective refraction. The mean cylindrical powers of Astigmatic Components of Subjective Refraction, Closed-view and Open-view were found to be $-0.689{\pm}0.516D$, $-0.691{\pm}0.530D$, $-0.470{\pm}0.507D$, respectively. The Difference of cylindrical Components between Subjective Refraction and Closed, Open-view were found to be $0.002{\pm}0.191D$, $0.015{\pm}0.137D$, respectively. Approximately 85% of Closed-view and Open-view autorefractor measurements were within ${\pm}20^{\circ}$ range of the difference of cylindrical axis with subjective refraction. The mean $J_0$ Components of Astigmatic Components of subjective refraction, Closed-view and Open-view were found to be $-0.155{\pm}0.332D$, $-0.004{\pm}0.178D$, $-0.001{\pm}0.156D$, respectively. The mean $J_{45}$ Components of Astigmatic Components, Closed-view and Open-view were found to be $-0.023{\pm}0.227D$, $-0.026{\pm}0.172D$, $-0.014{\pm}0.182D$, respectively. Both of the Closed-view and Open-view refractor showed available accuracy in measuring astigmatic components.

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Astigmatic Rainbow Hologram Using the Characteristics of Holographic Aberration (홀로그램의 비점수차 특성을 이용한 무지개 홀로그램 연구)

  • 홍석경;백성훈;김철중
    • Korean Journal of Optics and Photonics
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    • v.5 no.3
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    • pp.372-378
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    • 1994
  • A simple 2-step astigmatic rainbow holography method using the characteristics of holographic aberration is proposed. Point sources are used to record and reconstruct primary hologram. When the primary hologram is reconstructed, object image is divided into two components by the holographic astigmatism. This characteristics of holographic astigmatism and cylindrical lens power are used to obtain rainbow hologram of sharp image, no matter how far from the hologram the obseved image locates, in front of the hologram. And this hologram has optimum viewing distance long enough.enough.

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