• Title/Summary/Keyword: Ophthalmic optics

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Preparation and Investigation of Characteristics of Diamond-like Carbon Thin Films by Acetylene Plasma (아세틸렌 플라스마를 이용한 다이아몬드성 탄소 박막의 제작 및 특성)

  • Youk, Do Jin;Kang, Sung Soo;Lee, Won Jin
    • Journal of Korean Ophthalmic Optics Society
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    • v.3 no.1
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    • pp.1-8
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    • 1998
  • The a-C:H films have been grown on the glass substrate by PECVD mathod, where plasma was generated with a 60Hz line power source. The carbonization is checked from peak intensities of D($sp^3$) and G($sp^2$) peaks in Raman spectra. The hydronization and C-H bonding status in films can also be determined from FTIR results. Both the bonding strength of C-H and the ratio of $sp^3$ to $sp^2$ in bonding are found to be slightly dependent of partial pressure of $C_2H_2$. Judging from above results, we can conclude that the best value for partial pressure of $C_2H_2$ in growing process of thick films is about 15%.

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The Study on Relationship of Amblyopia and Astigmatism (약시와 난시와의 관계 연구)

  • Park, Hyun-Ju;Lee, Seok-Ju;Yim, Tae-Jun;Kim, Jai-Min;Lee, Ki-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.391-396
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    • 2004
  • For the prevention of amblyopia, early discover and treatment is very important. Therefore we evaluated the type and the degree of refractive errors of 39 children with anisometropic and refractive amblyopia aged 3 to 12 years, and studied the relationship of astigmatism and amblyopia. Astigmatism was found in 35 of 39 eyes. Of these 35 eyes, with the rule astigmatism was found in 30 eyes. The cylinderical power was distributed mostly from 0.50D to 6.50D and astigmatism did not appear to influence on the initial and final corrected visual acuity.

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A Test of Visual Acuity to Kindergarten's Children (유치원 원아의 시력측정)

  • Kang, H.S.;Seo, Y.W.;Kang, I.S.
    • Journal of Korean Ophthalmic Optics Society
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    • v.1 no.1
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    • pp.53-56
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    • 1996
  • In testing visual acuity of kindergarten's children, single Landolt's ring in chart projector was used under proper intensity of illumination. According to the result of 218 eyes' test, 0.6 V.A. forms 8.5 % at the age of 3, 0.7 V.A. forms 84.7 % at the age of 4, and 1.0 V.A. forms 6.8 % at the age of 5. However, children's visual acuity has been gradually developed with their growth. None of emmetropia can be found through the test. All of the children have ametropic eyes.

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A Comparative Study on Ophthalmic Lenses Standards (시력 보정용 안경렌즈의 규격 비교 연구)

  • Kwak, Ho-Won;Yu, Dong-Sik;Moon, Byeong-Yeon
    • Journal of Korean Ophthalmic Optics Society
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    • v.10 no.3
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    • pp.221-228
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    • 2005
  • In order to analyze the difference of lenses production, we measured the refractive power and the thickness of their optical centers using ophthalmic lenses which were distributed at home country and abroad. The home products were manufactured to be next to foreign goods, but there were several cases to exceed acceptable limits and we need to reduce the deviation from measuring values in the same lenses. To get a beat on advanced countries, rearing technical expert, hard quality test and process control and standardization of lenses are essential to home lens industrials.

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The Study of Wearing Spectacles in Elementary School (초등학교 아동의 안경장용에 대한 연구)

  • Lee, Hak Jun;Ahn, Cheon;Kim, Hong Gyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.4 no.2
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    • pp.87-90
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    • 1999
  • After we compared the Unaided visual acuity and the Corrected visual acuity who were wearing eyeglasses, over second grade of elementary school in Chonju and Iksan, we could get conclusions like these. 1. The grades are getting higher, there are more who are wearing eyeglasses. 2. Unaided visual acuity becomes worse but and Corrected visual acuity becomes better according to older. 3. There are 23 eye, (17.8%) in boys and 38 eye, (19.2%) in girls who have below 0.6 of the Corrected visual acuity who have to change their eyeglasses. 4. If Unaided visual acuity is getting better, Corrected visual acuity is betre. 5. There were 4 boys (6.2%) and 9 girls (9%) is Anisometropia.

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The Study on the Deficiency Color of the Elementary School (초등학교 아동들의 색각이상에 대한 고찰)

  • Lee, Hak Jun;Kim, Chang Sik;Kim, Hong Gyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.4 no.1
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    • pp.69-72
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    • 1999
  • Testing of color vision by Ishihara's test was followed in 1306 healthy elementary school students from 8 to 13 years old. The number of color deficiency was 27(2.07%) patients who consisted in 25(3.8%) boys among 654(male) and 2(0.31%) girls among 652(female). The male' s patients were definitely more than female's. The type of color deficiency were consisted in 10(37%) patients of red-green anomaly, 7(26%) patients of anomalous trichromatism, 6(22%) patient of red-green anopia and 4(15%) patients who were difficult to classify. All of patients were normal binocular vision and visual acuity.

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The Simulation of MAS-NMR Spectrum by the Voight Lineshape (Voight 함수를 이용한 MAS-NMR 스펙트럼 시뮬레이션)

  • Kang, Myoung Jin;Shim, Moon Sik;Ryu, Yung Rae
    • Journal of Korean Ophthalmic Optics Society
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    • v.2 no.1
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    • pp.17-24
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    • 1997
  • The Voight function which results from the convolution of the Gauss and Lorentz function is applied the MAS-NMR simulation of mixed alkali glasses and the glasses doped transition metal oxides. It is well known that the convolution of the Gauss and Lorentz function cannot be integrated in closed form for arbitrary values. So we make the new computer simulation program from which the Voight lineshape is obtained. The results are accorded well with the MAS-NMR spectra and we can find out the very small change of MAS-NMR lineshape.

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Diameter of the retinal blur circle in a artificial hypermetropia (인워적 원시에 따른 망막에서 착란원 크기)

  • Choi, Woon Sang;Kim, Yoon-Kyung;Oh, Heung Geun
    • Journal of Korean Ophthalmic Optics Society
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    • v.10 no.2
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    • pp.145-149
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    • 2005
  • In a artificial hypermetropia with the accommodative response, we investigated a diameter of blur circle as a function of test lens refractive power. In a schematic eye model of the hypermetropia, the second focal length along to accommodated power of the crystal lens are calculated as a function of test lens power and, also distance between the retina and exit pupil are calculated as a function of accommodated power. As these results are compared, the size of blur circle on the retina are obtained.

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Characteristic and Fabrication of Auto-Lensmeter using with Personal Computer (PC를 이용한 자동렌즈메타의 제작 및 특성 연구)

  • Park, Moon Chan;Choi, Hai Jung;Chen, Ko Hsein;Cho, Dong Soo
    • Journal of Korean Ophthalmic Optics Society
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    • v.6 no.1
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    • pp.31-35
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    • 2001
  • We have studied the auto-lensometer for several years in order to begin korean-made production of it and then developed the auto-lensmeter using with the personal computer. We introduce the most important principal of PSD device and the optical principal of measuring the power of the refraction of the lens by auto-lensometer and also explain the fabrication of the LED optical source system and PSD optical system. Finally, we found the power constant of our auto-lensmeter to be about 30 Diopter/mm.

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