• Journal of Korean Ophthalmic Optics Society
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• v.11 no.2
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• pp.99-107
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• 2006

The purpose of this study was to investigate the cause of discomfort come from wearing of soft contact lens(SCL) exposed to fundamental cosmetics, After SCLs were smeared with skin lotion, essence lotion or nutritional cream, they were exposed to artificial tear for 7 days, and then changes of the adhered protein amount, the transmission of visible light, the wettability and the base curve were estimated. The amount of protein adhered to SCLs were increased 3 times by being exposed to fundamental cosmetics. Moreover, the transmission of visible light of SCL exposed to both nutritional cream and artificial tear was 92.8%, which was 4.7% lower than SCL exposed only to artificial tear. By being exposed to skin lotion, essence lotion or nutritional cream, the contact angle of SCLs were increased up to $7.1^{\circ}$, $7.0^{\circ}$ or $5.7^{\circ}$ and the base curve of SCLs were decreased to 3.2%, 5.1% or 8.3%, respectively.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.305-311
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• 2019

The acrylic copolymer was designed and prepared for soft lens with high content. The copolymers were prepared using 2-hydroxyethyl methacrylate(HEMA) as a monomer and ethylene glycol dimethacrylate(EGDMA), glycerol dimethacrylate(GD), or glycerol 1,3-diglycerolate diacrylate (GDD) as a cross linking agent. The water content for high water content lens was 46%, which was higher compared to general purpose of 36%. The contact angle decreased from 38.6 to 34.4, which appears hydrophilic surface. The tensile strength decreased from 0.1 Mpato 0.08, then again to 0.05 as hydrophilic properties of cross linking agents increased. No phase separation was observed in the cross section of lens using scanning electron microscope. The real-time infrared technique was used in photo-polymerization. The initial polymerization rate increased from 0.6 to 0.9, depending on crosslinking agent.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.1
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• pp.31-42
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• 2014

Purpose: The present study was conducted to investigate the effect of the physical properties of RGP lens induced by lens polishing on the actual wearer's subjective comfort, the tear film break-up time and the blinking rate as a follow-up study that revealed the relationship between the lens physical properties during lens manufacturing and lens wearer's factors. Methods: RGP lenses made from the three different polishing conditions (25, 50 and 100 seconds) were applied on 28 eyes of 17 subjects, aged 20 to 29 years, without any known disease and surgical history in the eyes. While the subjects were asked to wear the RGP lenses longer than a week, the questionnaire for the comfortability was administered everyday. Subjective and objective tear break-up time and blinking rate of the wearers were further measured. Results: The wearer's subjective comfortability showed some difference in the type of discomfort and satisfaction score according to the polishing status when wearing RGP lenses made from different polishing conditions longer than a week, and a bigger difference in satisfaction score induced by polishing condition was especially shown in experienced RGP lens wearer rather than un-experienced wearer. In the case of RGP lens wearer compared with the ones without the wearing experience, as the wearing time increased subjective and objective tear break-up time were increased and the blinking rate was decreased. However, subjective and objective tear break-up time were tended to decrease with even longer wearing time when wearing the RGP lens made from the polishment for 100 seconds. Conclusions: These results confirmed that the optimization of physical properties of the lens may not give the same effect on the wearer's subjective and objective symptoms and other factors when actual wearing. From the results, it can suggest that the success rate of RGP lens wear may be changed by physiological factors such as the stabilization of wearer's tear film, comfortability and lens wearing experience when wearing RGP lens based on 'The manufacturing standard for soft contact lens/hard contact lens' provided by Korea Food and Drug Administration.

• Korean Journal of Optics and Photonics
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• v.18 no.2
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• pp.117-121
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• 2007

A fundamental problem in the in-line digital holography microscope is that the real image and virtual image and zero-order image are not separated spatially. In this paper, we have eliminated the zero-order noise by an averaging method and the twin image is divided using a geometrical set-up in an in-line digital holographic microscope. The size of the virtual image depends on the distance between the objective lens and the hologram plane and on the distance between the hologram plane and the image plane. We found that the virtual image size is smallest when the distance between the objective lens and the hologram plane is equal to the back focal length of the objective lens. We could divide the virtual image and real image by controlling the distance between the hologram plane and the objective lens.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.1
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• pp.15-20
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• 2002

The Hydroxyethyl methacrylate(HEMA) was developped in 1960's and later the use of contact lenses increased. At present more and more people use RGP contact lenses. Due to the wide range of optical corrections available and due to their high oxygen transmission Japanese and Korean people like them. Nevertheless one of nine CL users(beginners) stopped wearing the CL within the first year. We conducted a survey to evaluate the level of patient compliance in lens care and maintenance and to assess practitioner knowledge of contact lens information. Generally 6% of contact lens wearers drop out per year. The aim of this research was to find out what opticians can do to reduce the drop-out rate by getting information on handling, on general data of the patient and on optical prescription. Lens wearer were asked to complete a 10 question survey that focused on lens care-wear modality, lens replacement, storage, symptoms and case disinfection. There were total 180 participants in the study. Most of contact lens wearers have an inadequate understanding of contact lens care system. Therefore, it is important that contact lens specialists place more emphasis on practitioner education about general contact lens fields and reinforce patient education during the dispensing visit.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.117-124
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• 2015

Purpose: The purpose of this study was to compare the accommodative function of young adult in their 20s wearing monovision, modified monovision, and aspheric multifocal contact lenses at near task. Methods: Thirty young adults ($23.53{\pm}2.37years$) were fitted with monovision, modified monovision (the application of single vision contact lenses and center-near low addition aspheric multifocal contact lenses), and aspheric center-near multifocal contact lenses. After wearing these modalities during a week for adaption, and after watching visual display at computer for inducing accommodative pressure for 1 hour. The following assessments of accommodative function were made: contrast visual acuity (VA) at distance and near; accommodative response; near accommodative facility; and negative relative accommodation (NRA)/positive relative accommodation (PRA). All measurements were carried out binocularly. Results: In binocular distance VA with contrast of 10%, monovision was the worst among the four modalities (p=0.005). In accommodative response at 1 m (1.00 D), monovision was the lowest (p<0.05) and accommodative response at 40 cm (2.50 D) with monovision was lower than that of modified monovision and multifocal contact lens (p<0.05). We also found that there were no significant differences in accommodative facility and NRA/PRA among the four modalities. Conclusions: In young adult (20s), monovision with low add reduced the accommodative response at near task, however, modified monovision and multifocal lens with center-near type did not affect accommodative relaxation.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.1
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• pp.19-25
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• 2013

Purpose: The degree of the pupil covered with tinted region of circle soft contact lens was determined according to the illuminant conditions in everyday life and the change of visual acuity by its covering was further investigated. Methods: The circle contact lens having the non-tinted area of 6.2 mm in the center of the lens was applied on 82 eyes in their 20s and their minimum separable visual acuity and minimum legible visual acuity were determined under the luminances of 50 and 370 lux. Results: The covering of pupil was not found when wearing circle contact lens under 370 lux, however, some pupil covering ranged from 0.40 to 1.70 mm was observed in all subjects under 50 lux. The minimum separable visual acuity and minimum legible visual acuity were significantly decreased by the wearing of circle contact lens under 50 lux and the correlation between the larger pupil size of subjects and more decrease of visual acuity was observed. Furthermore, the decrease of minimum separable visual acuity was larger than the case of minimum legible visual acuity indicating that minimum separable visual acuity was largely affected by the covering of pupil. Conclusions: The consideration is necessary for the lens wearers and the manufacturers since the wearing circle contact lens in low-light indoor or nighttime activities may affect directly visual acuity.

• Proceedings of the Korea Contents Association Conference
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• 2016.05a
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• pp.87-88
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• 2016

서울시에 소재하고 있는 종묘와 사직단은 제례의식이 거행되던 곳으로 실제 재현은 1년에 약 한번 정도 진행되며 이것을 보기위해 관람객이 몰리게 된다. 이것은 일종의 병목현상처럼 일어나고 있다. 이러한 병목현상을 해소하고, 평소 관람객에게도 실제 재현과 같은 효과를 보여주기 위하여 실감형 콘텐츠를 활용하고자 한다. 마이크로소프트(MS)의 증강현실(AR)기기 '홀로렌즈(Hololens)' 기법을 바탕으로 관람자들에게 이용의 편의를 보완할 수 있는 방법을 제안한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.584-586
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• 2022

In this paper, we proposed an augmented reality(AR) service for the Great Gilt-bronze Incense Burner of Beakje - one of Korea's national treasures - using smart glasses. The proposed AR service was developed using Microsoft's HoloLens 2, MRTK, and Unity programs. The proposed service starts when the user wears HoloLens 2 and looks at a QR code next to the displayed the Great Gilt-bronze Incense Burner. Then, the proposed service visually provides users with the historical explanation of the Great Gilt-bronze Incense Burner and the objects in it. In particular, the proposed service augments virtual 5 musicians of the Great Gilt-bronze Incense Burner so that users can experience the performance culture of the Baekje era. Therefore, we can provide users with the value and meaning of the cultural heritage of the Baekje era as an expanded experience by using the virtual 5 musicians to overcome the current temporal and spatial constraints. We can confirm whether the proposed AR service is provided to users through HoloLens 2, in harmony with the Great Gilt-bronze Incense Burner of Baekje, a cultural heritage.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.173-180
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• 2000

To determine the effect of base curve and diameter of soft contact lenses on the fitting under the various corneal curvature, the model eyes which was made of either stainless steel or ordinary wood, were used as the substitutes for human eyes. The evaluations of fit of the soft contact lenses on both wood model eyes and human eyes were found to be very similar to each other. All the contact lenses except very thin ones became flat after fit on the stainless steel model eyes because the model eye could not preserve enough moisture to hold the edge of contact lenses on the steel ball's surface. The relationships between the base curves of contact lenses and radii of cornea for the optimum (normal) fit were measured as follows : corneal curvature (C.C)<7.6 mm : base curve(B.C) 8.4 mm, C.C 7.6~7.8 mm : B.C 8.4~8.5 mm. C.C 7.8~8.1 mm : B.C 8.6 mm. It is concluded that larger base curve is required for the eyes which have abnormal bulge on its cornea. It is found that very thin soft contact lenses can be easily twisted or folded regardless of moisture content when they were fit on the relatively dry eyes(corneas).