• Title/Summary/Keyword: Model eye

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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.

According to the Wavelength, the Analysis of Individual Eye Model's Aberration Change (파장에 따른 개별모형안의 수차변화 분석)

  • Kim, Se-Jin;Lim, Hyeon-Seon;Kim, Bong-Hwan;Kouh, Jeong-Hwi
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.3
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    • pp.61-64
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    • 2008
  • Purpose: The analysis of individual eye model designed from clinical demonstration about emmetropia shows that the aberration would be changed by the wave change. Method: The model on the basis of clinical demonstration of eye ball is designed in a form of having 4 refraction surfaces and a constant refractive index. We analyzed designed twelve individual eye model into aberrations changes, as giving changes Fraunhofer lines's six wavelengths. Result: About individual eye model, change in the wavelength of the wavefront aberrations analysis using the Zernike coefficient. This data indicate that the shorter wave is, the more defocus increases and the deviation value of spherical aberration and RMS are widened. Conclusion: As quantity of defocus according to result wavelength change is shorter and shorter, inclination which is similar twelve individual eye model is bigger and bigger and individual eye model majority of cases, little change, and change is shown in part individual eye model is a significant performance degradation can be raised.

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Optical constant of the reduced eye based on theoretical finite model eye (이론적 정밀모형안에 기초한 환산모형안의 광학상수)

  • 김상기
    • Korean Journal of Optics and Photonics
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    • v.15 no.3
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    • pp.268-273
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    • 2004
  • A finite model eye based on longitudinal spherical aberration is designed by an optimization method. Longitudinal spherical aberration for pupil diameter between 1 mm and 8 mm is graphed theoretically and compared with other model eyes. The chromatic dispersions are adjusted to fit experimentally observed chromatic aberration of the eye. This is a finite model eye with four a spheric refracting surfaces. It has an effective focal length of 15.842 mm. A designed reduced eye has an equivalent power of 63.12 Diopter, curvature radius of 5.281 mm, index of 1.33333, and axial length of 21.123 mm.

Lens Design of the Eyepiece Combined with the Accommodation-dependent Navarro Eye at an On-axis Point

  • Choi, Ka-Ul;Song, Seok-Ho;Kim, Sang-Gee
    • Journal of the Optical Society of Korea
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    • v.14 no.1
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    • pp.55-62
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    • 2010
  • We introduce a new method for lens design that combines an eyepiece with the finite model eye, to make a corrected version of the accommodation-dependent Navarro eye. The optical system that we designed, which includes a human eye, takes into account the aberration of the eye and increases the performance of the image in the retina. In the design results, for the optimized eyepiece combined with the corrected Navarro eye, visual acuity is 1.40. Compared with the existing method of eyepiece design using inverse ray tracing with the corrected Navarro eye, MTF value was recorded as 0.079 to 0.283 at 160 lp/mm and visual performance was improved.

Visual Performances of the Corrected Navarro Accommodation-Dependent Finite Model Eye (안구의 굴절능 조절을 고려한 수정된 Navarro 정밀모형안의 시성능 분석)

  • Choi, Ka-Ul;Song, Seok-Ho;Kim, Sang-Gee
    • Korean Journal of Optics and Photonics
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    • v.18 no.5
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    • pp.337-344
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    • 2007
  • In recent years, there has been rapid progress in different areas of vision science, such as refractive surgical procedures, contact lenses and spectacles, and near vision. This progress requires a highly accurate modeling of optical performance of the human eyes in different accommodation states. A new novel model-eye was designed using the Navarro accommodation-dependent finite model eye. For each of the vergence distances, ocular wavefront error, accommodative response, and visual acuity were calculated. Using the new model eye ocular wavefront error, accommodation dative response, and visual acuity are calculated for six vergence stimuli, -0.17D, 1D, 2D, 3D, 4D and -5D. Also, $3^{rd}\;and\;4^{th}$ order aberrations, modulation transfer function, and visual acuity of the accommodation-dependent model eye were analyzed. These results are well-matched to anatomical, biometric, and optical realities. Our corrected accommodation-dependent model-eye may provide a more accurate way to evaluate optical transfer functions and optical performances of the human eye.

Revised Computational-GOMS Model for Drag Activity

  • Lee, Yong-Ho;Jeon, Young-Joo;Myung, Ro-Hae
    • Journal of the Ergonomics Society of Korea
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    • v.30 no.2
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    • pp.365-373
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    • 2011
  • The existing GOMS model overestimates the performance time of mouse activities because it describes them in a serial sequence. However, parallel movements of eye and hand(eye-hand coordination) have been dominant in mouse activities and this eye-hand coordination is the main factor for the overestimation of performance time. In this study, therefore, the revised CGOMSL model was developed to implement eye-hand coordination to the mouse activity to overcome one of the limitations of GOMS model, the lack of capability for parallel processing. The suggested revised CGOMSL model for drag activity, as an example for one of mouse activities in this study, begins visual search processing before a hand movement but ends the visual search processing with the hand movement in the same time. The results show that the revised CGOMSL model made the prediction of human performance more accurately than the existing GOMS model. In other words, one of the limitations of GOMS model, the incapability of parallel processing, could be overcome with the revised CGOMSL model so that the performance time should be more accurately predicted.

THERMAL EFFECTS OF EYELID IN HUMAN EYE TEMPERATURE MODEL

  • Gokul, K.C.;Gurung, D.B.;Adhikary, P.R.
    • Journal of applied mathematics & informatics
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    • v.32 no.5_6
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    • pp.649-663
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    • 2014
  • Presence of eyelid on anterior ocular surface and its thermal effects play significant role in maintaining eye temperature. In most of the literatures of thermal modeling in human eye, the eyelid is not considered as an eye component. In this paper, finite element model is developed to investigate the thermal effects of eyelid closure and opening in human eye. Based on different properties and parameter values reported in literatures, the bio-heat transfer process is simulated and compared with experimental results in steady and transient state cases. The sensitivity analysis using various ambient temperatures, evaporation rates, blood temperatures and lens thermal conductivities is carried out. The temperature values so obtained in open eye show a good agreement with past results. The closure of eyelid is found to increase/decrease the eye temperature significantly than its opening, when the parameter values are considered to be at extreme.

Eye Localization based on Multi-Scale Gabor Feature Vector Model (다중 스케일 가버 특징 벡터 모델 기반 눈좌표 검출)

  • Kim, Sang-Hoon;Jung, Sou-Hwan;Oh, Du-Sik;Kim, Jae-Min;Cho, Seong-Won;Chung, Sun-Tae
    • The Journal of the Korea Contents Association
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    • v.7 no.1
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    • pp.48-57
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    • 2007
  • Eye localization is necessary for face recognition and related application areas. Most of eye localization algorithms reported thus far still need to be improved about precision and computational time for successful applications. In this paper, we propose an improved eye localization method based on multi-scale Gator feature vector models. The proposed method first tries to locate eyes in the downscaled face image by utilizing Gabor Jet similarity between Gabor feature vector at an initial eye coordinates and the eye model bunch of the corresponding scale. The proposed method finally locates eyes in the original input face image after it processes in the same way recursively in each scaled face image by using the eye coordinates localized in the downscaled image as initial eye coordinates. Experiments verify that our proposed method improves the precision rate without causing much computational overhead compared with other eye localization methods reported in the previous researches.

A Virtual Makeup Program Using Facial Feature Area Extraction Based on Active Shape Model and Modified Alpha Blending (ASM 기반의 얼굴 특징 영역 추출 및 변형된 알파 블렌딩을 이용한 가상 메이크업 프로그램)

  • Koo, Ja-Myoung;Cho, Tai-Hoon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.8
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    • pp.1827-1835
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    • 2010
  • In this paper, facial feature areas in user picture are created by facial feature points extracted by ASM(Active Shape Model). In a existing virtual make-up application, users manually select a few features that are exactly. Users are uncomfortable with this method. We propose a virtual makeup application using ASM that does not require user input. In order to express a natural makeup, the modified alpha blendings for each cosmetic are used to blend skin color with cosmetic color. The Virtual makeup application was implemented to apply Foundation, Blush, Lip Stick, Lip Liner, Eye Pencil, Eye Liner and Eye Shadow.

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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