• Journal of Korean Ophthalmic Optics Society
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• v.15 no.1
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• pp.105-116
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• 2010

Purpose: To analyze and compare differences between single vision lenses and functional progressive addition lenses and improvement to binocular visual function wearing functional lenses for pre-presbyopes altered their single vision lenses to functional progressive addition lenses with low addition. Methods: Healthy 32 subjects aged 24.03${\pm}$1.87 (male 23, female 9) who were recruited from university students wore functional progressive addition lenses (EYE-T, Chemilens Co., Korea, ADD 0.750) for 2 months. Objective refraction, corrected visual acuity at distance and near, near point of convergence, near point of accommodation, accommodative facility, phoria at distance and near were measured. And subjective satisfaction was investigated by using a questionnaire designed to fatigue, comfort, discomfort, overall satisfaction and preference. Results: Functional progressive addition lenses were better than single vision lenses at near point of convergence and accommodation, accommodative facility. Exo phoria measured at distance with single vision and functional progressive addition lenses. Exo phoria measured at near with functional progressive addition lenses was higher than that with single vision lenses. As a survey, the satisfaction was increased in questions related near work. However, single vision lenses were preferred in distance test of overall satisfaction, easy 10 adapt, lime to adapt. A survey showed thai preference of functional progressive addition lenses were increased 75.00% to 81.26% for near work, 50.00% to 65.63% for visual fatigue, 47.75% to 50.00% for visual comfort and 31.25% to 46.88% for overall comfort. Conclusions: Comparing between single vision lenses and functional progressive addition lenses, binocular visual function related near work, subjective satisfaction and preference was improved after wearing functional progressive addition lenses. This study suggested that functional progressive addition lenses were useful for long time near work.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.1
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• pp.73-78
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• 2010

Purpose: The purpose of this study was to examine diurnal variation of accommodation on people whose age are between 35 and 50 years old with frequent alternation of accommodation at period 1 (8:00-10:00), period 2(13:00-15:00) and period 3 (18:00-20:00). Methods: All \04 subjects were separated to nonpresbyopia and incipient presbyopia. Tests were done for amplitude of accommodation, accommodative facility and relative amplitude of accommodation. Results: Both nonpresbyopia and incipient presbyopia had the highest amplitude of accommodation in oculus dexter, oculus sinister and oculus uterque at period 2. In addition, the incipient presbyopia showed the statistical significance of daily change. The nonpresbyopia had the most accommodative facility at period 3 and incipient presbyopia had the most accommodative facility at period 2. Their daily variations were statistically significant. Both nonpresbyopia and incipient presbyopia had the most negative relative accommodation of daily change at period I. Both of them had the most positive relative accommodation at period 2. Conclusions: The incipient presbyopia had the highest amplitude of accommodation, accommodative facility. and positive relative accommodation (except the negative relative accommodation) at period 2.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.381-388
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• 2010

Purpose: This study was to compare the contrast sensitivity evaluated the visual ability at near wearing functional lenses for pre-presbyopes altered their single vision lenses to functional progressive addition lenses with low addition for 2 months. Methods: Healthy 32 subjects aged 24.03${\pm}$1.87 (male 23, female 9) who were recruited from university students wore functional progressive addition lenses(EYE-T, Chemilens Co., Korea, ADD 0.75D) for 2 months. Corrected visual acuity at distance and near and contrast sensitivity at near were tested right after wearing functional progressive addition lenses to compare wearing single vision lenses. And we had second test after 2 months later. Results: Comparing between test and retest, contrast sensitivity at near wearing functional progressive addition lenses was improved more than wearing single vision lenses at all spatial frequency of right, left and both eyes. Conclusions: There was considered that contrast sensitivity test is useful to evaluate the visual ability as well as quality of near work and can be applied variously.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.3
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• pp.369-375
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• 2015

Purpose: The current study was performed to estimate the changes in reading speed and blinking rate according to different background colors when reading paper book and further investigate their correlation. Methods: Twenty-nine adults (10 males, 19 females) who consented to the present study and had no ocular disease, ocular surgery history showing normal binocular vision were participated into the study. The subjects were asked to read the novels with black letter printed on white, red, green and blue background for 15 min, respectively. Then, the reading speed per page and blinking rate per page were measured during reading and analyzed according to background colors. Results: Reading speed per page according to the background color showed a tendency to accelerate in the white and green background as the reading time increased however, it was almost unchanged in the blue background and rather decelerated in the red background. On the other hand, the blinking rate per page tended to decrease in all background as the reading time was increased however, the smallest reduction was shown in the red background. There was a correlation that the reading speed increased as the blinking rate decreased in all backgrounds and the best correlation was shown in the green background. Conclusions: From the results, a correlation between the increasing reading speed and the reducing blinking rate while reading paper book with same demand on accommodation and convergence was confirmed however, the change in blinking rate and reading speed was varied depending on the main wavelength of light. It might mean that the working speed and visual fatigue can be varied depending on the difference of main wavelength when doing near work. Thus, it can be suggested that the adjustment of working environment and conditions should be made according to the kind of required perception.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.3
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• pp.265-274
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• 2016

Purpose: The aim of this study was to evaluate relationship between worker's ophthalmoxerosis symptom and IAQ (Indoor Air Quality) variation after planting indoor plants at newly-built office building. Methods: We selected a new office building located in Sejong-si and occupants who work in the Office for study. The indoor air pollutant was investigated according to applying indoor plants. The indoor air quality of the new building was evaluated by measuring volatile organic compounds (VOCs), aldehydes, temperature and humidity. The level of dry eye symptoms was classified into normal, mild, moderate and severe by using the Ocular Surface Disease Index (OSDI). Results: There was VOCs' reduction effect according to placing indoor plants because the concentration of VOCs in newly-built government office (Sejong-si) was highly decreased when the indoor plants was placed at the office. The occupants' SBS (Sick Building Syndrome) symptoms score was gradually decreased in accordance with applying indoor plants. However, SBS symptoms score was increased when the office was not applied indoor plants. There was not statistical significance in workers' dry eye questionnaire results. Conclusions: There was reduction effect of indoor air pollutant in applied indoor plants office. Also, in case of questionnaire results of ophthalmoxerosis and SBS (Sick Building Syndrome) symptoms score were showed positive effect. This study is needed longer-term study because of complements of difference of individual sensitivity and there are some limitations due to field survey research.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.37-42
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• 2008

Purpose: The objective of the study: At present, the spectacles, with its use as a medical aids or a fashion trimming, are recognized as one of the living necessities which can't be separated from human body. One of the features of spectacles is that it must be worn on any part of human body. Such a feature has to be satisfied under the condition an user keeps feeling comfortable with the rim of spectacles worn. In order to ensure meeting this condition, a criterion has to be arranged for the design of the rim of spectacles. In order to manufacture a rim of spectacles which allows an user to secure a comfortable range of vision as well as enhancing the feeling when to be worn, a manufacturing standard has to be established based on optical science. No precise rim of spectacles could be made from the manufacturing method depending on the manufacturer's sensibility. When the rim of spectacles was manufactured according to the incorrect standards, it may cause an user such a fatal result as myopia, hyperopia or astigmatism. Methods: This study focuses on providing a detailed explanation about the design of rim, which is the most important element during designing a rim of spectacles, making use of the optical elements of spectacles, and helping the manufacturers and the people who work in the spectacles-related business understand and recognize what is correct and exact and then leading them to establish a standard in respect to the manufacture and selection of spectacles. Results, Conclusions: Considering the fact there happen many errors in relation with the names of rim stipulated in the provisions of International Standards Organization (ISO), due to wrong interpretation by some of the rim manufacturers, the right interpretation should be given about the bridge which is directly connected to rim, so that the rims of spectacles manufactured in Korea could keep a favorable position in competing with the foreign products of same kinds.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.1-6
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• 2008

Purpose: Plastic optical monomer materials having ultra high refractive index have an income of the whole quantity from advanced nations to domestic companies which are related to plastic optical lens. It is necessary to develop novel plastic optical lens materials in order to overcome a FTA provision and revitalize a stagnating optical lens industry in the interior optical lens industries. The new plastic optical lens materials against the substitution effect of income should be gradually demanded. This work will be synthesized novel super high refractive monomer resin materials of urethane lens series and studied the properties of optical lens using it. Methods: ETS-4 (2-(2-mercaptoethylthio)-3-{2-[3-mercapto-2-(2-mercaptoethylthio)propyl thio]ethylthio}propane -1-thiol), which is optical lens monomer resin having super high refractive index, was synthesized and identified its structure and property by elemental analysis, EI-MS, TGA, FT-IR spectroscopy, $^1H$ and $^{13}C$ NMR spectroscopies. After mixing evenly from mixed monomer resin and diisocyanate series, it was casting in glass mold. After thermal curing, the obtained optical lenses were measured and compared with the refractive index and Abbe number for studies of their optical properties. Results: We have synthesized the novel ultra high refractive index monomer resin, ETS-4, and have identified its structure and property by elemental analysis, EI-MS, TGA, FT-IR spectroscopy, $^1H$ and $^{13}C$ NMR spectroscopies. The existence of three isomers for EST-4 was identified by $^{13}C$ NMR spectroscopy. The refractive index ($N_d$ at $25^{\circ}C$) of monomer resin in liquid state obtained from the Abbe refractometer was 1.647. The refractive indexes of raw plastic optical lenses prepared from the mixed ETS-4 monomer and diisocyanate series were in the range of 1.656~1.680. Conclusions: Novel super high refractive index plastic optical lens monomer was synthesized and analysed, the optical lenses prepared using it were colorless transparency and excellent properties. It is of utility for the industrialization.

• Korean Journal of Oriental Medicine
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• v.16 no.3
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• pp.15-22
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• 2010

Objective : This study aims to search Four-constitution Medicine based acupuncture by investigators and its effect on constitution-specific symptoms. Method : Among 463 oriental medical doctors who are the members of society of Four-constitution Medicine, 191 results are collected. The items of the questionnaire are sex, age, work experiences, working type, constitution diagnosis & prescription, the use of constitution acupuncture and so on. Result : The proportion of acupuncture treatment applied constitution-based acupuncture to patients are "Must Use" 12.6%, "Almost Use" 14.1%, "Sometimes Use" 42.9% and "Never Use" is 1.0%. The average ratio of patients treated by constitution-based acupuncture to all patients is 47%. 1. Digestive tract disease is found to be the most effective disease with constitution based acupuncture. Musculoskelectal problems, cardiovascular disease, respiratory disease, neuropsychiatric disease and urogenital disease are followed. On the oriental medicine, spleen system disease is the most frequently applied and heart system disease, neuropsychiatric disease, liver system disease, locomotorium disease and pulmonary system disease are followed. 2. Acupuncture therapeutic measures are different according to disease. For example, Sa-am acupuncture is the most widely used for spleen system disease, locomotorium disease, heart system disease, neuropsychiatric disease, pulmonary system disease. Eight constitution medicine acupuncture is effective for ophthalmic & otolaryngologic disease. Conclusion : This study is to investigate constitution-based acupuncture technique. In conclusion, the most widely used technique is Sa-am acupuncture and it is the most successful in treating digestive tract disease.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.910-914
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• 2010

A collision between a barge and an oil tanker of Hebei Spirit caused the release of an estimated 12,547 tons of light crude oil into the Yellow Sea off the west coast of Taean-gun, Korea on December 7, 2007. This study was aimed to evaluate exposure conditions and acute health effects in soldiers participating in the Hebei Spirit oil spill cleanup activities and the association between these and the nature of the work and use of protection devices. The sample comprised 2,624 soldiers stratified by working area and number of working days. We divided working area into the coast of Taean-gun(highly polluted area) and other areas affected by Hebei Spirit oil spill. And we divided number of working days into 1-7 days, 8-14 days, 15-21 days and above 22 days. Data were obtained via a structured, self-administered questionnaire and included information on working area, type of working, number of working days, use of protective materials, and acute health effects. Acute health effects were classified into 5 groups: neurological, respiratory, dermatologic, ophthalmic and other symptoms. Data analysis was performed using unconditional logistic regression used to compute odds ratios and 95% confidence intervals. On logistic regression analysis, working on the coast of Taean-gun was significantly associated with increased risk of acute health problems: headache, dizziness, nausea, general fatigue, insomnia, flushed face, sore throat, dry throat, runny nose, cough, sputum, skin irritation, sore eyes, injection of conjunctiva, tear, and low back pain. Furthermore soldiers working more than 21 days were significantly associated with increased risk of acute health problems: insomnia, flushed face, sore throat, runny nose, cough, sputum, tear, low back pain and fever. Accordingly, the exposure to the oil and the subsequent cleanup efforts were suggested to inflict acute health problems on soldiers participating in the Hebei Spirit oil spill cleanup activities.

• Journal of Technologic Dentistry
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• v.35 no.4
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• pp.367-376
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• 2013

Purpose: The purpose of this study is to investigate self management and subjective chewing ability and provide the basic information to research of healthy life of old people from development of education and method for dental health of denture patient. Methods: From 15th or August to 15th of September in Daegu and Gyeong-buk, denture patients were targeted for a survey. Data from 295 people were analyzed. Results: Adjusted $R^2$ of oral health and denture satisfaction of an object of study increased to 24.9%(F=20.460, p<.001). Adjusted $R^2$ of denture custody and method of sterilization was 37.8% and Adjusted $R^2$ of recognition denture satisfaction of chewing effect was 14.4% which affect to most(F=9.274, p<.001). Conclusion: In conclusion denture condition, denture custody, method of sterilization, chewing effect influence oral health, healthy life of patients who have denture.