• Title/Summary/Keyword: Ophthalmic

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A Study of Relationship between Refractive Error Correction and Phoria Amount (눈의 굴절이상 교정과 사위와의 관계)

  • Seo, Yong Won;Kim, Dae Nyoun;Kang, In San
    • Journal of Korean Ophthalmic Optics Society
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    • v.5 no.1
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    • pp.139-146
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    • 2000
  • Once refractive error of the eye was fully corrected, Maddox rod was used to investigate binocular vision function. When the deviations of subjects' eyes were measured, orthophoria. without any horizontal deviations, was found in 10%, esophoria in 55% and exophoria in 34% of the patients. Esodeviation of the eye was found to be greater than exo-deviation by 11%. This is also refracted in deviations found to be greater than $4{\Delta}$ diopter magnitude where esophoria was 23% and exophoria was 9%. Thus for the patients to achieve comfortable binocular vision function, binocular vision anomalies need to be considered in spectacle prescription. In examining ocular anomalies of corrected refractive error, the deviation of the eye differed from under corrected refractive power to over corrected refractive power. There was a decrease in exophoria and an increase in esophoria, with over correction. This was thought to be due to accommodation. Furthermore, calculated AC/A ratio was found to vary from 1.25 to 6.61 and its relationship to refractive error could not be determined.

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Availability of Astigmatism Expectation by Jin's and Beam Project Chart (진용한 시력표와 투영식 시력표에서 난시량 예측의 용이성)

  • Kim, Sang-Moon;Kang, Hye-Sook;Shim, Hyun-Seog
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.1
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    • pp.53-58
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    • 2012
  • Purpose: The purpose of this study was to predict the amount of astigmatism through logMAR visual acuity by Jin's chart at best vision spherical power and to compare availability of astigmatism expectation by Jin's and beam project chart. Methods: LogMAR and decimal visual acuity were measured for 150 college students and visual acuity and compared the amount of astigmatism under full correction. Results: Jin's chart was showed marked differences at least more than 0.25 D intervals per line than beam project chart. Correlation with the amount of astigmatism was higher the logMAR visual acuity r = 0.8578 than decimal visual acuity r = -0.7199. Conclusions: LogMAR visual acuity at best vision spherical power was able to predict to amount of astigmatism and Jin's chart was easier than beam project chart to predict difference of each lines.

Study and Research of Seller's Optical Knowledge About Sale of Goggle or Sun-glasses (고글 및 선글라스의 판매에 대한 판매인의 안경 지식에 관한 연구)

  • Lee, Ji-Min;Jo, Hyun-Rae;Jang, Woo-Yeong
    • Journal of Korean Ophthalmic Optics Society
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    • v.14 no.4
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    • pp.1-10
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    • 2009
  • Purpose: Recently because goggle and sunglasses is industrial products, unprofessional is selling in store what is not optical store. Due to layman's sale, check of frames or lens, the quality, curve, A/S, is impossible. Therefore layman's sale threated national eye-health. So we investigated in order to know them, merchant of goggle and sunglasses except for optician, about "how many they have optical knowledge?" and "What can they give a service us?" Methods: Regardless age, we get a survey of 208 person who purchased goggle and sunglasses in a store that it is not optical store and 100 of goggle and sunglasses except for optician. Results: Most merchant who haven it knowledge about glasses sells goggle or sunglasses. Even though merchant has knowledge about glasses, It was very littles, now. Conclusions: Optician who have expert knowledge need method that it was very littles. So goggle and sunglasses that it is registered industrial products need method to transform into health instrument.

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The Electrical and Optical Characteristics of ATO Films Prepared by RF Magnetron Sputtering Method (RF 마그네트론 스퍼트링법에 의해 제조된 ATO 박막의 전기적 및 광학적 특성)

  • Kang, Sung Soo;Lee, Sung Ho;Jang, Yoon Seok;Park, Sang Chul
    • Journal of Korean Ophthalmic Optics Society
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    • v.15 no.4
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    • pp.299-305
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    • 2010
  • Purposes: The purposes of this study were to investigate the optical, structural and electrical properties of the antimony doped tin oxide(ATO) thin films according to certain variable deposition conditions, such as RF input power and T-S (target-substrate) distance change, using transparent conducting oxide (TCO). Methods: ATO thin films of Sb concentration ratio with $SnO_2:Sb_2O_5$ = 95:5 wt% were deposited at room temperature by RF magnetron sputtering method. Results: ATO thin films were most sensitive to the RF input power: light transmittance was 78% at RF input power of 30W, and 0.56 nm for the surface roughness and 1007 $\Omega{\cdot}cm^{-2}$ for the sheet resistance as well. Conclusions: It was found that ATO thin films were showed the large change in its characteristics of structural, optical and electrical properties which were affected by T-S distance and RF input power.

The Research on the Optical Reliability of Spectacle Lens in Korea (국내 안경렌즈 광학적 요소 신뢰성 조사)

  • Kim, Tae-Hun;Ye, Ki-Hun;Sung, A-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.1
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    • pp.43-48
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    • 2008
  • Purpose: This study is to evaluate reliability of geometrical optics properties of spectacle lenses by using ISO and the medical instrument standard of KFDA, which are being sold in Korea. Methods: We used samples of three hundred and ninety eight spectacle lenses of eight company in total. Refractive indices of each samples which were used in experiment were classified into three groups of medium index (1.55~1.56), high index (1.60~1.61) and extra high index (1.67). Results: Conformity of refractive power was 81.61% in total spectacle lenses. The results showed that thickness conformity 90%, appearance conformity 85.18%, size conformity 96.23% and optical center point conformity 99.50% in total. Conclusions: We found that they deviated from the permitting value in many spectacle lenses on refractive power. The results of errors on prism power, surface inspection and optical center point showed small values in total products. In experiment of lens size and thickness, the bulk of indication rates and conformities of samples deviated from the permitting errors.

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Evaluation of Resistive Index Using Color Doppler Imaging in Canine Ophthalmic Vasculature (개의 안혈관에 대한 컬러도플러초음파를 사용한 저항지수의 평가)

  • Lee, Hee-Chun;Yoon, Jung-Hee
    • Journal of Veterinary Clinics
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    • v.20 no.2
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    • pp.145-149
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    • 2003
  • Color Doppler imaging(CDI) was carried out to determine CDI-derived resistive index(RI) values of normal canine ophthalmic vasculature and its reproducibility. CDI was performed on 58 dogs. and normal ranges of RI value were calculated for the medial long posterior ciliary artery(mLPCA), ciliary artery(CA), and ophthalmic artery(OA). Ophthalmic vascular RI values of normal dogs were 0.67$\pm$0.07, 0.70$\pm$0.06, and 0.80$\pm$0.04 in mLPCA, CA, and OA, respectively. Means of RT value of all vessel had no statistically significant difference by sex, fellow orbits, and skull type. The results suggest that color Doppler imaging is a noninvasive test which has the advantage of providing objective measurements of blood flow velocity parameter in the canine eye and orbit.

Refractive Error Shift in Nuclear, Cortical, and Subcapsular Cataract (핵, 피질 그리고 낭 백내장의 굴절이상 전환)

  • Park, Sang-Chul;Lee, Soek-Ju;Sung, A-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.8 no.1
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    • pp.41-45
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    • 2003
  • The researchers have studied on the effect of three main morphological types(nuclear, cortical, and subcapsular cataract) of age related cataract on refractive error. We also identified that spherical and cylinderical shift in each type of morphological cataract accoding to their locations and effect of intraocular pressure before and after cataract surgery. Nuclear cataract showed myopic shift while cortical cataract showed hyperopic shift, and subcapsular cataract showed not significant changes on both direction. Age related cataract subjects(120 eyes) only were recruited from sun-cheon area. We use optic section of slit lamp biomicroscope to identify the anatomical location of cataract, and optimal refractive correction determined by objective(retinoscope) and subjective refraction then spherical changes were calculated from the spherical eqivalent value. Intra-ocular pressure were measured by auto-tonometer before and 7 days after cataract has been replaced by IOL. The change in cylindrical power, usually A-P diameter decreased according to increases of age, A-P diameter increased because intra-ocular pressure rises by progression of cataract and this convertion with the rule astigmatism to against the rule astigmatism and this increases more by intra-ocular pressure.

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Persistent Photoconductivity in Hydrogenated Amorphous Carbon Thin Films (수소화된 비정질 탄소 박막에서의 지속광전기전도도)

  • Kang, Sung Soo;Lee, Won Jin;Sung, Duck Yong
    • Journal of Korean Ophthalmic Optics Society
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    • v.1 no.2
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    • pp.49-55
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    • 1996
  • Hydrogenated amorphous carbon(a-C:H) films were fabricated by the low-frequency (60Hz) glow discharge of the mixture of methane and hydrogen, and their electrical properties were investigated. We observed that a-C:H films show the persistent photoconductivity(PPC) by illumination of heat-filtered while light for a few seconds. The PPC was about 10 times larger than the annealed dark conductivity. The samples clearly showed metastable characteristics. With increasing illumination times from 1 to 100 min, the annealing activation energy of the PPC was about 0.39eV. The annealing temperature at which the PPC disappeared increasing from $100^{\circ}C$ to $130^{\circ}C$. Illumination longer than 80 min leads to the formation of ${\pi}$ defects and to the decrease of PPC. From these results, we tentatively propose that the states in the ${\pi}$ band act as deep trap centers generating the metastabilities.

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The Need for Change of Korean Optician(optometrist) System (안경사제도의 변화 필요성에 대하여)

  • Seo, Jae-Myoung;Kim, Jae-Do;Kim, Heung-Soo;Shim, Hyun-Suk;Kim, Sang-Hyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.4
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    • pp.527-536
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    • 2015
  • Purpose: In this paper, we have dealt with problems and improvement of korean optician system. Methods: Using the relevant material of korean optician system and international optometrist system, provides the theoretical basis of the need for regulatory changes optician. Results: The people with refractive errors are increasing, 67% of refractive error test is made from optical shop and korean optician are sufficient trained, many opticians are in charge of the refractive error test at the ophthalmic hospital. We have confirmed that current law does not reflect adequately the nature of optician's work. Conclusions: Since current capacity of the Korean opticians and education system ready to provide health services for people, therefore an korean optician must redefine the law to fit the reality.

Estimation of Total Astigmatism Quantity from Corneal Astigmatism on Koreans in Their Twenties (한국인의 20대에서 각막난시에 의한 전난시량의 예측)

  • Yoo, Jong-Sook;Yu, Dong-Sik;Han, Kyung-Ae;Kim, Se-Jin;Wi, Sung-Hyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.4
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    • pp.151-154
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    • 2008
  • Purpose: Javals' rule is a commonly used formula for estimating total astigmatism from corneal astigmatism. Many researchers suggested a modication of Javals' rule. Therefore, we estimated the total astigmatism on the basis of measurements of corneal astigmatism and assessed the accuracy of Javals' rule. Methods: We estimated the total astigmatism on the basis of measurements of corneal astigmatism on 108 eyes of 54 subjects of koreans in their twenties. Results: The regression of the total astigmatism from corneal astigmatism is less than 1.25 of Javals' rule, but it was equivalent to Auger's modified Javals' rule. Conclusions: The regression equation for this study was as follows: Total Astigmatism=0.79 (Corneal Astigmatism)-0.49D${\times}$90.

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