• Title/Summary/Keyword: Schematic eye

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Design of the Schematic Eye of Koreans using the Clinical data (한국인 안구의 임상자료를 통한 모형안 설계)

  • Kim, Bonghwan;Kim, Sejin;Lim, Hyeonseon;Ji, Taeksang
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.1
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    • pp.117-124
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    • 2004
  • In this paper, we took the clinical data of Korean eyes and designed the schematic eye with the same optical properties of the real eye. In the design process, we took the clinical emmetorpia data of young Korean adults collected in the past and analyzed to get a basic specification of the real eye for the design of schematic eye. The purpose of design was for the schematic eye to have the same optical properties of real eye in spherical aberration and astigmatism.

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Simulations of Finite Schematic Eyes for Presbyopia Using the Navarro Eye Model (Navarro 모형안을 이용한 노안 정밀모형안의 전산모사)

  • Kim, Shin-Hwa;Kim, Dal-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.3
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    • pp.301-309
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    • 2015
  • Purpose: This study was aimed to design new schematic eyes for presbyopia using the Navarro eye model and clinical data. Methods: We collected clinical data of eye-optical parameters of males in their age of 40, 50, and 60 from previous studies, and designed schematic eyes for presbyopia using the ZEMAX program. Results: The presbyopic process and features of the designed schematic eyes well accorded with the clinical data of previous studies. Conclusions: On the basis of the Navarro eye model, a finite schematic eyes for presbyopia were newly designed corresponding with clinical data.

Design of the Finite Schematic Eye with the Crystalline Lens with GRIN Index (실안의 수정체 굴절률 분포를 갖는 정밀모형안 설계)

  • Kim, Bong-Hwan
    • Korean Journal of Optics and Photonics
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    • v.18 no.2
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    • pp.167-170
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    • 2007
  • In this study, clinical data for emmetopia in young Koreans was taken in order to design the finite schematic eye, which had optical properties of real eyes including spherical aberration, astigmatism, field curvature and distortion. Furthermore, the crystalline lens with GRIN medium was optically analyzed, and the finite schematic eye with the GRIN crystalline lens was designed.

Optimum design of the finite schematic eye using spherical aberration (구면수차를 이용한 정밀모형안의 최적화)

  • 김상기;박성찬
    • Korean Journal of Optics and Photonics
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    • v.13 no.3
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    • pp.266-271
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    • 2002
  • The finite schematic eye based on spherical aberration and Stiles-Crawford effect is designed by an optimization method. It consists of four aspherical surfaces. The radius of curvature, thickness, asphericity, and spherical aberration are used as constraints in the optimization process. Stiles-Crawford effect in the pupil is considered as a weighting value for optimum design. The designed schematic eye has effective focal length of 20.8169 mm, back focal length of 15.4820 mm, front focal length of -13.8528 mm, and image distance of 15.7150 mm. When the pupil diameter is 4 mm, the diameter of entrance pupil and exit pupil are 4.6919 mm and 4.2395 mm, respectively. From the data of 75 measured Korean emmetropic eyes, this finite schematic eye is designed first in Korea.

Evaluation of scale accuracy and effect of off-the-visual-axis on schematic retinoscope training eye (검영기 훈련 모형안의 굴절상태 눈금과 벗어난 시축의 평가)

  • Ryu, Dong-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.10
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    • pp.3789-3793
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    • 2010
  • To investigate accuracy of graduated scale of schematic retinoscope training eye(schematic eye) and induced effect when measured at off-axis from visual axis. Two skilled retinoscopist measured refractive power using retinoscope in random order. Seven schematic eyes from a single manufacturer were recruited and set to mark +4.00 to -6 diopter(+4, +3, +2, +1, 0, -1, -2, -3, -4, -5, -6). After introducing +2.00 diopter trial lens(50cm working lens), neutral distance was measured at 180 degree to estimate accuracy of scale, and refractive power measured at 0, 5, 10, 15 and 20 degree off-axis to see if any error was induced. According to the results measured by two specialists, in six of seven schematic eye, scale setting varied (p<0.05) and measured refractive power at 5, 10, 15 and 20 degree off-axis from visual axis were $-0.13{\pm}0.06$, $-0.29{\pm}0.06$, $-0.58{\pm}0.11$, and $-0.83{\pm}0.16$ diopter respectively. In some schematic eye, scale graduated on the schematic eye and scale measured by retinoscopy could be different and if retinoscopy is performed off-axis from visual axis, any measuring error can be caused.

Comparison of the Optical properties of Schematic Eyes by using the Seidel aberrations (자이델 수차를 이용한 모형안의 광학적 성능 비교)

  • Kim, Bong-Hwan;Lim, Hyeon-Seon;Ji, Taek-Sang
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.269-280
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    • 2004
  • For the studying of the optical property of the human eye by using the Seidel aberrations with schematic eyes, we have used the several paraxial and fine schematic eyes. In another world, after fixing the iris ot aperture pinhole on the anterior of lens, we investigated how the surface contributions and the surface asphericity affected the optical properties of schematic eyes by using the Seidel aberration coefficients variation. Also, by analysis of dividing both a relaxed state and the accommodation state of the eye, we investigated the change of the optical properties during the change of accommodation.

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Optical Performance Analysis of the Eye which it Follows in Iris Eccentricity (홍채 편심에 따른 눈의 광학적 성능 분석)

  • Kim, Bong-Hwan;Han, Sun-Hee
    • Journal of Korean Ophthalmic Optics Society
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    • v.14 no.2
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    • pp.31-34
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    • 2009
  • Purpose: We are to analyze optically how to affect the eye related with movement of the iris. Methods: Using the schematic eye to have the crystalline lens of the radial GRIN and the spherical GRIN forms that come to be planned in existing, the iris centre was moved 0.5 mm with nasal direction in order to be identical with the real eye. Also, considering that the iris centre move according to increase of the pupil size, the iris centre was moved 0.4 mm with temporal direction to analyze the optical performance change of the eye respectively. Results: Because of decrease in the spherical aberration, the schematic eye with nasal direction 0.5 mm eccentricity of the iris showed a different consequence plentifully compared with the performance of the real eye. Besides, the schematic eye with temporal direction 0.4 mm eccentricity of the iris showed that the spherical aberration somewhat increased. Conclusions: In case of design of the schematic eye with the similar real eye performance which the iris centre was moved 0.5 mm with nasal direction, we need to research about aspheric coefficient of optical constants of each refracting surface considering the performance change of a spherical aberration, a peripheral power error and astigmatism etc, owing to change of the real eye hence to be affected by the iris movement.

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An Analysis of Optical Performance of the Finite Schematic Eye According to Iris Eccentricity and Visual Axis change (시축 변화와 홍채 편심에 따른 정밀모형안의 광학적 성능 분석)

  • Kim, Bong-Hwan;Han, Sun-Hee
    • Journal of Korean Ophthalmic Optics Society
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    • v.15 no.2
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    • pp.151-154
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    • 2010
  • Purpose: We investigated how the movement of iris and visual axis affects the finite schematic eye Methods: Using the schematic eye with the crystalline lens in the existing forms of the radial GRIN and the spherical GRIN, the iris centre was moved 0.5 mm in nasal direction and visual axis was tilted $5^{\circ}$ in same direction, with the additional degree of 2.5 down to locate the focal point in fovea. This study analyzed performance change of the optical system, designing it same as the real eye. Results: The whole aberration distribution showed a considerable difference in performance in comparison with the real eye; the biggest difference shown at the central field of optical system. The spherical aberration showed the biggest difference, and a peripheral power error and field curvature leaned toward (+) direction in aberration distribution. Conclusions: When designing the schematic eye with the performance similar with that of the real eye by taking into consideration the iris centre and visual axis, the aberration at the center field of optical system in particular should be corrected. Spherical aberration which showed the biggest difference should be corrected in the first place. In addition, a peripheral power error and field curvature that leaned toward (+) direction should be moved toward (-) direction.

Design of the Finite Schematic Eye with GRIN Crystalline Lens Considering Iris Eccentricity (홍채 편심을 고려한 GRIN 수정체를 갖는 정밀모형안 설계)

  • Kim, Bong-Hwan;Han, Sun-Hee
    • Journal of Korean Ophthalmic Optics Society
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    • v.16 no.1
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    • pp.61-64
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    • 2011
  • Purpose: The purpose of this study was to design the finite model eye with GRIN lens similar to actual eye, which considered the effect of iris eccentricity on eyes. Methods: By using the finite model eye with Radial GRIN and Spherical GRIN, which were designed previously, the location of iris was eccentrically located by 0.5 mm in the direction of nose to show the same eye as actual one. For ray trace and design, Code V program of Optical Research Associates (ORA) was adopted. Results: Designed model eye was compared to actual eye depending on iris eccentricity and the model eye which showed reduced value was corrected according to actual eye to design the finite model eye. Conclusions: Ocular optical systems considered the point that iris was a rotational asymmetry and designed the finite model eye with GRIN lens, which was similar to actual eye, by considering the effect of iris eccentricity on eye.

Design and Analysis of the human eye model using new approximation for the crystalline lens (새로운 수정체 모델을 적용한 모형안의 설계 및 분석)

  • Gang, Eun-Gyeong;HwangBo, Chang-Gwon;Park, Seong-Chan
    • Proceedings of the Optical Society of Korea Conference
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    • 2009.02a
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    • pp.535-536
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    • 2009
  • This paper presents a new approximation for the crystalline lens of the human eye with refracting surfaces based on schematic eye during accommodation. A new model eye describes the iso- indical profiles in the form of symmetric spherical surfaces. A vary important condition which was imposed upon the parameters (thickness, radius) was the lens volume conservation during accommodation.

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