• Title/Summary/Keyword: photopic vision

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Transmittance measurement for thickness control of ITO layer (ITO막의 두께 제어를 위한 투과율 측정)

  • 박정규;이무영
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.213-213
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    • 2000
  • A sensor system which can measure the transmittance of ITO(Indium Tin Oxide) layed glass is proposed. The sensor system includes a single wavelength laser beam source, photo diodes and electronic circuit processing sensor signal. The wavelength of laser is 543.5 m, this is most sensitive wavelength to photopic and scotopic vision. We applied the sensor to measure transmittance of ITO layer on general manufacturing environment and verified the effectiveness of sensor through experimental measurement.

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Comparison of Contrast Sensitivity Between Soft Contact Lens Wearers and Spectacle Wearers (콘택트렌즈와 안경 착용자의 대비감도 비교)

  • Kim, Jai-Min;Lee, Min-Ah
    • Journal of Korean Ophthalmic Optics Society
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    • v.12 no.4
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    • pp.119-125
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    • 2007
  • The aim of the present study was to compare the contrast sensitivity of soft contact lens wearers, spectacle wearers or emmetropia. Seventy myopic eyes and thirty emmetropic eyes aged 19 to 26 years were collected. The myopic group included 48 eyes corrected with spectacle lenses and 22 eyes of them corrected with contact lenses, too: all had corrected vision acuity of 20/20 or better. Spatial contrast sensitivity was measured using the OPTEC 6500 contrast sensitivity view-in tester included the EyeView  Functional Vision Analysis software at photopic or mesoopic condition. There was no significant difference in contrast sensitivity between spectacle lenses and emmetropes. Myopes corrected with soft contact lenses showed statistical sensitivity losses at 1.5, 12 cycle/degree spatial frequencies. In conclusion, our findings suggest that loss of contrast sensitivity in soft contact lens wearers might be interpreted as evidence for corneal disruption before corneal pathological events occur in contact lens wearers. Contrast sensitivity testing appears to be a useful method for evaluating soft contact lenses.

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The Changes of VEP Values According to the Luminance Conditions and Refractive Errors in Normal Persons (정상인에서 조도와 굴절이상도에 따른 시유발전위 검사 값의 변화)

  • Leem, Hyun Sung;Lee, Koon Ja
    • Journal of Korean Ophthalmic Optics Society
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    • v.12 no.4
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    • pp.111-117
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    • 2007
  • The visual evoke potential(VEP) is the effective method to diagnose and treat the amblyopia or to check the infants visual ability. In order to evaluate the changes of P100 latencies and amplitudes of VEP by intensity of illumination and refractive errors, we measured latencies and amplitudes of 41 normal adults (20/20 VA) who have no ocular diseases and neurologic diseases. The results were as follows: In the scotopic condition, the latencies were N75$75.83{\pm}3.69$ msec, P100$103.48{\pm}5.34$ msec, the P100 amplitude was $14.86{\pm}2.43$ msec, and in the photopic condition, the latencies were N75$76.71{\pm}3.11$ msec, P100$107.26{\pm}5.54$ msec and the P100 amplitude was $10.35{\pm}1.75$ msec. The latencies and amplitudes of P100 in the photopic condition had higher values than those in the scotopic condition and the measures were significantly different between the scotopic and photopic condition (p<0.01). The P100 latencies were delayed both in the scotopic and photopic condition with the refractive errors and those measures were delayed more than in the photopic condition. The P100 amplitudes in the induced myopic and hyperopic conditionsreduced than in the emmetopes in both illumination conditions. The P100 latencies and amplitudes in emmetropes showed a correlation with the induced myopic conditions in the scotopic condition. Those results showed that P100 latencies and amplitudes are dependent on the illumination conditions and refractive errors. And we suggest that those results would be useful to determine and evaluate the normal range for the person considering patients' refractive errors and illumination of the test room.

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Change of Spherical Aberration with Aspheric Soft Contact Lens Wear (비구면 소프트콘택트렌즈 착용에 의한 눈의 구면수차 변화)

  • Kim, Jeong Mee;Mun, Mi-Young;Kim, Young Chul;Lee, Koon-Ja
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.4
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    • pp.365-372
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    • 2012
  • Purpose: To investigate ocular higher order aberrations (HOA) and spherical aberration changes caused by an aspheric soft contact lens designed to reduce spherical aberration (SA) of the eye. Methods: Fifty subjects who have successfully experienced soft contact lenses were refitted with aspheric design (Soflens Daily Disposable: SDD, Bausch+Lomb) soft contact lens. Ocular higher order aberrations (HOA) and stand alone SA were measured and analyzed for a 4-mm pupil size using Wave-Scan Wavefront$^{TM}$ aberrometer (VISX, Santa Clara, CA, USA). High and low contrast log MAR visual acuity and contrast sensitivity function (CSF) were also measured under photopic and mesopic conditions (OPTEC 6500 Vision Tester$^{(R)}$). All measurements were conducted monocularly with an undilated pupil. Results: The RMS mean values for total HOA with SDD contact lenses were significantly lower than those at with unaided eyes (p<0.001) and a reduction for SA in the SDD was close to the baseline SA (zero ${\mu}m$) (p<0.001). For the SDD lens, there was a statistically significant correlation between the changes in the total HOA and the contact lens power (r=0.237, p=0.018) as well as between the changes in SA and the lens power (r=0.324, p=0.001). High contrast visual acuity (HCVA) and low contrast visual acuity (LCVA) with SDD lenses were $-0.063{\pm}0.062$ and $0.119{\pm}0.060$, respectively under photopic and $-0.003{\pm}0.063$ and $0.198{\pm}0.067$, respectively under mesopic condition. Contrast Sensitivity Function (CSF) with SDD lenses under both photopic and mesopic conditions was $3.095{\pm}0.068$ and $3.087{\pm}0.074$, respectively. Conclusions: The SDD contact lens designed to control SA reduced the total ocular HOA and SA of the eye, resulting in compensating for positive SA of the eyes. Thus, the optical benefits of the lens with SA control would be adopted for improving the quality of vision.

Luminous efficiency's estimation method of transmitted light in lenses (렌즈에서 투과된 광의 시감도 추정 방법)

  • Kim, Yong-Geun
    • Journal of Korean Ophthalmic Optics Society
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    • v.8 no.2
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    • pp.163-168
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    • 2003
  • The eye sensitivity in the difference conditions of a light source intensity consists of two functions by the receptor of cone and rod according to a wavelength. We derived a distribution function of $P{\lambda}=A{\cdot}e^{-({\lambda}-{\lambda}_u)^2/2W^2}$ using a respond probability of the receptor of cone-rod for a photon. It was well applied for a CIE eye's sensitivity curve of a wavelength. When there is lens In front of eye, luminous efficiency should be corrected. Transmission light which permeate to depends on absorption wavelength, and relationship of final luminous efficiency's estimation method is expressed by multiplication of luminous efficiency and transmittance intensity of lens. $$Pf({\lambda})=T({\lambda}){\cdot}P({\lambda})$$. The theory was applied to photopic and scopic vision with brown color lens.

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Contrast Sensitivity and Glare with Spherical and Toric Soft Contact Lenses in Low-astigmatic Eyes (구면과 토릭 소프트 렌즈로 교정한 약도 난시안의 대비감도와 눈부심)

  • Lee, Min-Ah;Kim, Hyun Jung;Kim, Jai-Min
    • Journal of Korean Ophthalmic Optics Society
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    • v.14 no.1
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    • pp.39-45
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    • 2009
  • Purpose: The purpose of this study is to compare the visual performance by contrast sensitivity (CS) and disability glare (DG) in low astigmatic eyes corrected with toric soft lenses and other optical corrections. Methods: Twenty university students with myopia (-1.00 to -6.50D Sph. with astigmatism up to 1.50 cyl) were enrolled and corrected by five different methods: 1) soft toric lenses; 2) spherical soft contact lenses; 3) RGP lenses; 4) best spectacle corrected visual acuity; 5) spherical equivalent spectacles. All subjects had corrected vision acuity of 20/20 or better. Contrast sensitivity and disability glare were measured using the OPTEC 6500 contrast sensitivity view-in tester included the EyeView Functional Vision Analysis software at photopic or mesopic conditions with glare. Results: At photopic condition, best corrected spectacle wearers had the highest monocular contrast sensitivity at all spatial frequency followed by soft toric lenses, RGP lenses, spherical equivalent spectacles, and spherical soft contact lenses. However, all of them were in normal contrast sensitivity value at photopic condition. At mesopic condition with glare, toric soft lenses were the highest and followed by RGP lenses, spherical equivalent spectacles, best spectacle corrected visual acuity and spherical soft contact lenses. It was observed that spherical soft contact lens wearers demonstrated lower range than normal contrast sensitivity value at mesopic condition with glare. Conclusion: Toric soft lenses gave better visual performance than spherical soft lenses in low astigmatic eyes. Subjects requiring the use of contact lenses under mesophic conditions could benefit from toric soft lenses.

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Morphology of Retinas and Lenses in the Fish of the Genus Zacco (Cypriniformes, Cyprinidae): Possible Relationship with Prey and Habitat

  • Lim, Jae-Won;Lee, Chung-Lyul;Lee, Moo-Sam
    • Animal cells and systems
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    • v.7 no.4
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    • pp.331-335
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    • 2003
  • Vertebrates with different habitats have different proportions of visual cells, with the rod cells responding to scotopic vision and the cone cells responding to photopic and color vision in their retinas. The present work studied whether the kinds and arrangement patterns of the cone cells and interlocking morphology of the lens were related to the kind of preys and habitats in the genus Zacco. The retinas were observed by a light microscopy using H-E staining method and the interlocking formula of the lens fibers were investigated by a scanning electron microscopy. The interlocking formula of the lens fibers of Z. temmincki is an ' anchor and socket ' connection, and that of Z. platypus is a ' ball and socket ' connection. The cone cells of Z. platypus and Z. temmincki constituted compacted mosaic patterns of row type. Away from the center, the double and single cone cells gradually increased in diameter. Zacco temmincki had identical double cone cells and Z. platypus had non-identical double and single cone cells. The eyes of Z. temminckifeeding on a moving aquatic insects in relative limpid water and swift current of mid and upper stream have better resolution than that of Z. platypus feeding on mainly adhesive algae and some aquatic insects in slightly turbid water of mid stream.

Study on Visibility of Road Lighting Source in Fog conditions (안개 발생시 도로 조명용 광원의 시인성 연구)

  • Cho, Moon-Sung;Kim, Yung-Kyun;Jung, Kwan-Jin;Lee, Jung-Uk;Kim, Hoon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.6
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    • pp.1-7
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    • 2007
  • In this paper, It evaluated visibility about Metal Halide Lamp(MHL), High Pressure Sodium Lamp(HPS) and PLS(Plasma Lighting System) as Road lighting source in fog conditions. To evaluate visibility, it analyzed valuation of subjects about each light sources in special fog conditions. In result, it obtained that High Pressure Sodium Lamp has best visibility in photopic vision and PLS has best visibility in scotopic vision. This result is expected to help about select of Road lighting source.

The Photoreceptor Populations in the Retina of the Greater Horseshoe Bat Rhinolophus ferrumequinum

  • Kim, Tae-Jin;Jeon, Young-Ki;Lee, Jea-Young;Lee, Eun-Shil;Jeon, Chang-Jin
    • Molecules and Cells
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    • v.26 no.4
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    • pp.373-379
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    • 2008
  • Recently, we reported the existence of AII "rod" amacrine cells in the retina of the greater horseshoe bat Rhinolophus ferrumequinum (Jeon et al., 2007). In order to enhance our understanding of bat vision, in the present study, we report on a quantitative analysis of cone and rod photoreceptors. The average cone density was $9,535cells/mm^2$, giving a total number of cones of 33,538 cells/retina. The average rod density was $368,891cells/mm^2$, giving a total number of rods of 1,303,517 cells. On average, the total populations of rods were 97.49%, and cones were 2.51% of all the photoreceptors. Rod: cone ratios ranged from 33.85:1 centrally to 42.26:1 peripherally, with a mean ratio of 38.96:1. The average regularity index of the cone mosaic in bat retina was 3.04. The present results confirm the greater horseshoe bat retina to be strongly rod-dominated. The rod-dominated retina, with the existence of AII cells discovered in our previous study, strongly suggests that the greater horseshoe bat retina has a functional scotopic property of vision. However, the existence of cone cells also suggests that the bat retina has a functional photopic property of vision.

Comparison to Contrast Sensitivity of Male and Female Adults in Their 20s (20대 성인 남녀의 대비감도 비교)

  • Choi, Soon-Lyoung;Han, Kwang-Lae;Shim, Hyun-Suk
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.1
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    • pp.87-92
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    • 2014
  • Purpose: Comparison with contrast sensitivity between binocular and monocular of 20s adult was measured by spatial frequency 3.0, 6.0, 12.0 and 18.0 cpd and compares difference between monocular and binocular and difference between male and female. Methods: Topcon CV-3000 Phoroptor was used for full correction of 99 ophthalmic optics students and contrast sensitivity were measured by using Vector Vision CSV-1000E at 2.5 m in photopic condition (100 $cd/m^2$). Results: Photopic condition at 2.5 m, average contrast sensitivity of entire subject was 52.54, 80.40, 36.79 and 13.56 with right eye and 52.33, 81.29, 41.73 and 14.22 with left eye in 3, 6, 12 and 18 cpd. For both eye 65.46, 113.69, 52.04 and 19.44 were measured. The contrast sensitivity of male was 58.22, 83.52, 37.89 and 13.82 with right eye and 56.03, 46.68 and 15.67 with left eye in spatial frequency of 3, 6, 12 and 18 cpd. Both eyes were measured to 70.89, 120.96, 56.56 and 19.89. The contrast sensitivity of female was 46.50, 77.09, 35.61 and 13.28 with left eye and 48.40, 70.43, 36.47 and 12.68 with left eye in spatial frequency of 3, 6, 12, 18 cpd. Both eyes were 59.68, 105.97, 47.23 and 18.95. Conclusions: Contrast sensitivity value of binocular shows higher than monocular to both male and female. Contrast sensitivity of difference between male and female were statistically remarkably higher to male in right eye 3 cpd, left eye 6 cpd, 12 cpd and both eye 3 cpd. In other frequency, there was no statistical significance but male shows higher.