• Title/Summary/Keyword: 암순응

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Objective Measurement of EEG-based Dark Adaptation (EEG기반 암순응의 객관적 계측)

  • Kye, Seula;Wee, Yejin;Lee, OnSeok
    • Proceedings of the Korea Information Processing Society Conference
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    • 2019.10a
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    • pp.1149-1150
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    • 2019
  • 눈은 일상생활을 하기 위한 필수적인 부위로 지속적으로 눈 건강을 관리할 필요가 있다. 최근 눈 건강에 대한 관심이 높아지면서 암순응 이상 탐지의 중요성 또한 부각되고 있지만 암순응을 측정하는 기존 방법들은 시간이 오래 걸리거나 주관적인 가능성이 있다. 이에 본 연구는 사람의 정신적인 활동에 즉각적으로 반응하는 뇌파 변화를 통해 암순응 이상을 탐지하는 시스템을 개발하고자 하였다. 제안한 시스템은 개발한 암순응 측정 환경을 VR기기를 통해 응시하면서 실시간으로 뇌파를 탐지하며 눈이 어두운 환경에 적응하였을 때 나타나는 뇌파의 변화를 감지하여 암순응 이상을 탐지한다. 본 연구를 통해 향후 뇌파측정기와 암순응에 관한 연구에서 다양한 활용 가능성을 보여준다.

A Study of a Decay Parameter for the Dark Adaptation Function on the retina (망막에서 암순응 함수의 Decay parameter 연구)

  • Kim, Yong Geun
    • Journal of Korean Ophthalmic Optics Society
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    • v.5 no.2
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    • pp.145-150
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    • 2000
  • The adaptation for a right source on the retina consists of the light-dark adaptation's two curves for a time by the rod-cone receptor. We obtained the adaptation for a time to measure the threshold intensities, it was two decay curves by the center of a rod-cone break. It could be represented the dark adaptation by a exponential decay function consisting of $T_{min}$, $a_r$, $a_c$, $T_{0(r)}$, $T_{0(c)}$, $t_b$, $t_c$'s parameters. The curves of a $t_b$ below and a $t_b$ above showed the adaptation sensitivity of the cone and the rod. The exponential decay function was well applied to the dark adaptation in difference retinal positions, in contrally fixated fields, in luminous, as age etc. It could be used the decay parameter as the index because of representing the properties of the dark adaptation's function.

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Scotopic Pupil Size in Myopes (근시안에서 암순응상태의 동공크기)

  • Jeong, Woo-Jae;Jeon, In-Chul;Kang, Ji-Hun
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.2
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    • pp.197-202
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    • 2013
  • Purpose: This research was performed to measure and analyze scotopic pupil size in myopes and to figure out the factors that influence it. Methods: The pupil size of 191 healthy myopic subjects were measured with the pupillometer (Colvard pupillometer, OASIS medical, USA) in scotopic and analyzed with the age, corneal size, spherical equivalent refractive error, corneal curvature. In addition, it was compared with the measurements of intra-examiner and inter-examiner to verify reproducibility of pupillometer. Results: The mean (${\pm}$SD) scotopic pupil size was $6.64{\pm}0.68$ mm (range, 5.00~8.00 mm), the lower age and the larger corneal size, The bigger the pupil size. The lower spherical equivalent refractive error and steepper corneal curvature tends to be smaller. The reproducibility of intra-examiner and inter-examiner in pupillometer showed the reliability highly (Guttman splithalf point > 0.91). Conclusions: The pupil size associated with age, corneal size, spherical equivalent refractive error and corneal curvature in scotopic condition. It can refer to prevent inconvenience that may occur RGP contact lenses, cataract surgery and refractive surgery.

The Combination Style Emergency Lighting Fixture which Considers a Dark Adaptation (암순응을 고려한 겸용형 비상조명등)

  • Yoon, Cheol-Gu;Choi, Hong-Kyoo;Lee, Guen-Moo;Kim, Young-Kyu;Kim, Jong-Soo;Chang, Min-Kee;Hwang, Sang-Gu
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.10a
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    • pp.145-148
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    • 2009
  • It is sharply decreasing from several hundred[lx] to 1.0[lx] when it turn on the emergency lamps. The sharply decreasing illuminance makes peoples to have dark adaptation for long time. And they were with fear and confused. It also causes secondary accidents by people who take a mistake. This paper studied the combination style emergency lighting fixture to improve a problem of dark adaptations. But it was made an assumption that same conditions of battery capacity and a number of emergency lamps.

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The Optical Characteristics of 240 W High Power LED Fish Luring Lamp (240W급 고출력 LED 집어등의 광학적 특성)

  • Bae, Jae-Hyun;An, Heui-Chun;Kim, Sang-Woo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.6
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    • pp.681-687
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    • 2013
  • This study analyzed characteristics of 240 W high power LED lamps by comparing with those of traditional metal halide lamps. In addition, it analyzed the propriety of LED lamps as a source of light, considering seawater transmission characteristics. When Applying white LED package with the color temperature color temperature of 6500K, a 240W-LED fishing lamp has a characteristics of the luminous angle to be expanded to ${\pm}45^{\circ}$, the illumination change was improved to 0.8, as well as the luminance efficiency was improved to 98.8lm/W. As results of comparison between one 1,500W-metal halide lamp and four 240W-LED lamp with considering a seawater transmission and a luminous efficiency of scotopic vision, the radiant flux of two lamps were almost equal level at 50m depth and the luminous flux was 5% higher LED lamp than metal-halide lamp even if only applying the luminous efficiency of scotopic vision. As the luminous flux of LED lmap was 14% higher than that of metal-halide lamp with applying the luminous efficiency of scotopic vision to radiant flux at 50m depth, so LED fishing lamp was verified to alternative possibility of metal-halide lamp.

Visual Recognition Delayed in Time by Electromagnetic Wave (전자파에 의해 시간 지연되는 시각인식)

  • Yun, Jae-Hyun;Park, Hyung-Jun
    • Proceedings of the KIEE Conference
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    • 2005.07d
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    • pp.2947-2949
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    • 2005
  • 본 연구의 목적은 전자파에 노출되었을 경우와 노출되지 않았을 경우의 시각 자극(광자극)에 의해 발생하는 뇌파를 분석하여, 전자파가 광자극 전과 광자극 후의 시각인식에 미치는 영향을 규명하는 것이다. 암순응 시킨 피험자에게 신호의 주파수가 약 900MHz이고, 세기가 약 13dBm인 전자파에 노출되었을 경우와 노출되지 않았을 경우로 구분하여, 광인식시에 발생하는 뇌파를 계측, 분석하였다. 본 연구에서 제안한 해석방법을 이용하여 뇌파를 분석한 결과, 인체가 전자파에 노출되었을 때 시각인식에 기인하여 나타나는 뇌파 변화의 현상 중 $\alpha$-blocking 시점이 지연되는 것을 확인하였다.

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A Study on the Convertible Emergency Lighting Fixture in Consideration of Dark Adaptation (암순응을 고려한 겸용형 비상조명등에 관한 연구)

  • Yum, Sung-Bae;Yoon, Cheol-Gu;Lee, Jung-Eun;Shin, Hye-Young;Song, Young-Joo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.4
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    • pp.24-29
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    • 2011
  • When an emergency light turns on due to a blackout, the intensity of illumination is drastically changed from hundreds [1x] to 1.0[1x]. This sharp change of illumination intensity not only lowers the darkness adaptation of the eye, it also degrades the obstacle cognitive ability of the evacuees, resulting in secondary critical accidents due to anxiety, and fear. Thus, this study proposed a convertible emergency lighting fixture that controls the rate of speed of light in two stages by time with darkness adaptation of the eye in consideration. In addition, the effect of such emergency light is verified by suggesting an illumination simulation without increasing the number of light or capacity of battery to make it economically feasible.

Development of the Elderly-oriented Visual Function Measuring System (노인을 대상으로 하는 시각 기능 측정 시스템 개발)

  • Kim D. U.;Park E. J.;Kim D. W.
    • Proceedings of the KAIS Fall Conference
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    • 2005.05a
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    • pp.115-118
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    • 2005
  • 대부분의 제품을 만들 때 그 기준은 젊은 사람들의 기준으로 만들어진다. 이것들은 노인들이 사용하는 노인용품을 만드는데 있어서 적절하지 알은 기준이다. 노인들이 사용하는 제품을 만드는데 있어서 노인들의 기준을 적용하기 위해 실측자료를 기반으로 데이터베이스의 구축이 필요하다. 본 연구에서는 노인들을 대상으로 하는 시각 기능 측정 시스템을 구축하기 위해 landoltC환과 contrast를 이용한 암순응과 glare를 이용하여 생활시력을 측정하고, 측정된 자료들을 이용하여 데이터 베이스를 구축하고자 한다.

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Development of An Optometric Questionnaire for the Elderly Suitable for Optical Shops in Korea (한국 안경원 실정에 맞는 노안용 문진표의 개발)

  • Noh, Young-Jin;Kim, Dal-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.15 no.2
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    • pp.161-167
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    • 2010
  • Purpose: The aim of this study was to help the rapid and effective eye-tests of old patients by developing an optometric questionnaire for the elderly suitable for optical shops in Korea. Methods: We surveyed several previous studies about the age-related changes of the eye, and deduced 10 items which were appropriate for optometric eye-tests. Excluding the items that could be easily found in a routine eye-test and that was just physiological changes, we principally chose anomaly items which could be catched by simple oral questions. The questionnaire was mainly composed of clinically important items that were frequently observed. Results: To diagnose optometric symptoms related to eye-aging, we listed 15 questions on the questionnaire for the elderly. Each of the 15 questions was respectively about the decline in the amplitude of accommodation (no.1), anisometropia (no.2), xerophthalmia (no.3), muscae volitantes (no.4-5), dark adaptation (no.6) light and dark adaptation (no.7), contrast sensitivity (no.8), contrast sensitivity and anisometropia (no.9), contrast sensitivity and colour vision (no.10), the field of view (no.11), stereoscopic vision (no.12), colour vision (no.13), cataract (no.14), and presbyopia (no.15). Each question was easy to understand and related to the generally observed symptoms. Conclusions: Our optometric questionnaire for the elderly, which was developed by the procedure mentioned above, was expected to be a help for examining the aging eye and offer the basis of eye-tests of older patients in Korean optical shops.

Vision and Aging

  • Kim, In Suk;Hilz, Rudolf
    • Journal of Korean Ophthalmic Optics Society
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    • v.7 no.1
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    • pp.9-13
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    • 2002
  • It is well known that the maximum amplitude of accommodation decreases with increasing age.(Presbyopia). With single vision lenses presbyopia can be corrected only for one viewing distance. With progressive power lenses presbyopia can be corrected for all viewing distances. But there are some other changes in the visual system with age which can not be corrected by spectacle lenses. Pupillary diameter decreases and the light transmission of the ocular media decreases. Therefore old people need more light, they need better illumination. Cone density in the retina decreases, this is only one example for changes in the sensory system. These changes in the visual system cause changes in visual functions. At the age of 80 visual acuity has decreased to half. Contrast sensitivity for gratings decreases mainly for high spatial frequencies very important is the increase of stray light in the ocular media and therefore the increase of glare. Veiling luminance increases by a multiple of approximately 4, Dark adaptation gets slower and light sensitivity is approximately 2 log units (factor 100) less when the eye is completely dark adapted. Also colour vision gets worse, especially at low luminances. Elderly people have problems with visual tasks which require divided attention between foveal and peripheral vision. An example is the measurement of the useful field of view. This useful field of view be expanded (improved) by visual training.

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