• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.71-76
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• 2007

The aim of this study was to investigate level of understanding of symptoms appearing after wearing rigid gas permeable contact lens for optometrists, and if they were educated high about rigid gas permeable contact lens, they could increase the probability of wearing success of rigid gas permeable contact lens as dividing into an adaptative symptoms and an abnormal symptoms. For 96 optometrists a questionnaire about apparatuses, protocol and experience for prescription of rigid gas permeable contact lens and level of understanding of symptoms appearing after wearing rigid gas permeable contact lens was performed. Results showed that level of understanding of rigid gas permeable contact lens was very low, and education was performed for optometrists.

• 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.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.11a
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• pp.43-45
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• 2013

본 논문은 안경착용 얼굴영상을 위한 실시간 눈 인식 알고리즘을 제안한다. 학습 알고리즘에 기반한 기본의 눈 인식 방법은 안경을 착용한 얼굴영상이 입력으로 주어질 경우 안경의 다양한 크기와 색깔, 형태로 인해 알고리즘의 학습 효율이 크게 떨어져 낮은 눈 인식 성능을 갖게 된다. 제안하는 방법은 모폴로지 연산을 통해 얼굴영상에서 안경이 포함된 부분을 검출하여, 안경으로 인한 눈 인식 알고리즘의 성능저하를 막는다. 성능평가를 위해 제안하는 방법을 Viola & Jones의 눈 인식 학습 기반 눈 인식 알고리즘에 적용하였으며 Spacek의 얼굴영상 데이터베이스를 실험 영상으로 사용하였다. 실험 결과, 제안하는 방법은 기존 눈 인식 알고리즘의 처리속도를 15fps (frames per second)에서 14.2fps로 하락시키면서 인식률을 75%에서 96.3%로 향상하였다.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.93-96
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• 2007

Research was taken its place in Dong wun elementary school in Gwang ju city. Subject ages were somewhere around 9 to 13. Among total number of 1,196, subjects with emmetropia were 384 people (32.1%), with 22.56% of 9 year old students, 16.01% of 10 year old student, 36.45% of 12 year old student, 39.11% of 13 year old. When age increases, the rate of emmetropia increase as well. Gender dependence of emmetropia rato was 31.07% for boys and 33.33% for girls, which proves girls with higher emmetropia ratio than boys. Among subjects with binocular vision acuity lower than 0.7, those require spectacles, only 37.5% of 9 years old students, 30.3% of 10 year old students, 44.64% of 12 year old students, and 30% of 9 year old students were wearing glasses. It shows that spectacle-wearing ratio is very low in spite of visual acuty lower than 0.7.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.231-240
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• 2006

This study conducts a questionnaire survey of 492 middle school students in Jeju islands about the rate of using glasses/contact lens, the place and time of visual acuity test, the period of changing the glasses, the purchase price, the mason to change the glasses, the interrelationship between wearing spectacles and residential district, etc. The results are as follows: 1. 45.33% of the object of investigation use the glasses or contact lens to correct their visual acuity. Among them, the student who wears only glasses is 93.27%, the student who wears glasses and contact lens together is 5.83%, the student who wears only contact lens is 0.90%. 2. As for the period of changing his(her) glasses, below 6 month is 20.18%, from 6 month to one year is 52.02%, from one year to two years is 20.18% and more than two years is 7.62%. 3. As for the purchase price to change his(her) glasses, below 30,000won is 13.45%, from 30,000won to 50,000won is 43.50%, from 50,000won to 70,000won is 23.77%, from 70,000won to 100,000won is 15.25% and more than 100,000won is 4.03%. 4. As for the reason of changing his(her) glasses, cause of change of visual acuity is 55.16%, by broken frame and lens is 27.35%, as want to just change his(her) spectacles is 14.80% and as the others is 2.69%. 5. As for the relative importance in purchasing glasses, the student who thinks more frame is 16.59%, the student who thinks more lens is 67% and the student who thinks both frame and lens is 58.74%. 6. As for the frist time of visual acuity test, 1 grade of elementary school is 37.2%, 3 grade of elementary school is 12.56%, 4 grade of elementary school is 11.66% and 6 grade of elementary school is 11.66%. 7. As for the place of visual acuity test to determine the Dptr. of glasses which wear now, opitican's shop is 57.85% and ophthalmic clinic is 42.15%. 8. As for the frist time of wearing the glasses or contact lens for correct his(her) visual acuity, the most of answer(21.97%) is at 6 grade of elementary school. 9. As for the reason why does not wear the glasses or contact lens though his(her) naked binocular vision is below 0.8, as does not feel any difficulty in daily life is 62.5%, as know that the more wear, the more decrease his(her) visual acuity is 15.65%, by economical circumstance is 6.24% and as not good externally is 15.63%, respectively.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.43-48
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• 2008

Purpose: This study is to evaluate reliability of geometrical optics properties of spectacle lenses by using ISO and the medical instrument standard of KFDA, which are being sold in Korea. Methods: We used samples of three hundred and ninety eight spectacle lenses of eight company in total. Refractive indices of each samples which were used in experiment were classified into three groups of medium index (1.55~1.56), high index (1.60~1.61) and extra high index (1.67). Results: Conformity of refractive power was 81.61% in total spectacle lenses. The results showed that thickness conformity 90%, appearance conformity 85.18%, size conformity 96.23% and optical center point conformity 99.50% in total. Conclusions: We found that they deviated from the permitting value in many spectacle lenses on refractive power. The results of errors on prism power, surface inspection and optical center point showed small values in total products. In experiment of lens size and thickness, the bulk of indication rates and conformities of samples deviated from the permitting errors.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.2
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• pp.57-63
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• 2003

To investigate the RMS SD(Root Mean Square Spot Diameter) in a back focal plane as the front surface power, the center thickness, and the refraction index vary, we use programs which are Cove V and LOSA 2.0, and consider a spectacle lens with back vertex power of -4.00D and diameter of 70 mm. We also consider the front surface power varied from 0.00 to 10.00D, the center thickness varied from 1.1 to 2.0 mm, and the indices which are $n_d$ = 1.498, 1.523, 1.586, and 1.660, respectively. As the front surface power increases the RMS SD in the back focal plane increase rapidly. When the refraction index increases, the RMS SD in the back focal plane decrease and the variation of RMS SD in the back focal plane decreases as the front surface power increases. When the center thickness of spectacle lens increases, the RMS SD in the back focal plane is constant and the edge thickness of that increases. We know from these results that the image in the back focal plane of a spherical spectacle lens improves as the front surface power increases and the refraction index decreases.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.373-378
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• 2014

To investigate the wear status of contact lenses by analyzing care of contact lenses container and actual condition of people wearing contact lenses and in Gyeonggido. The results were based on a questionnaire survey of 200 people who are the students of the middle school, the high school and the college among the clients of opticians to purchase contact lenses for six months from January 2013 to July 2013. According to the poll, the highest number of those polled, 139 (55.16%) people, said they were wearing cosmetic color contact lenses. Female respondents and male respondents were in the proportion of 177 (88.5%) to 23 (11.5%), respectively. 37 people (18.5%) who responded said "yes" to the question of them sharing contact lenses and glasses. 103 people (51.5%) answered "no" to the question of regularly replacing their lens containers. 148 people (74%) answered "yes" to the question of having glasses in order to investigate contact lens wearers user rate of glasses. The highest number of respondents, 127 people (63.5%), said "middle school" was the first time that they wore contacts. Meanwhile, 65 people (43.92%) said they initiated wearing glasses at 4th-6th grades. It is considered that it is necessary using proper contact lenses suitable for the clients' eye health in order of vision correction, rather than for cosmetic purposes. The role of the optician is considered to be very important for the proper management of the appropriate contact lens hygiene and regular optical check-ups of the contact lens wearers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.482-487
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• 2016

Ultra-violet rays are very harmful to eye health care. The blocking of ultra-violet rays and a reduction of optical reflection in the visible light range, which is to increase the share of transmitted light, and avoid the formation of ghost images in imaging, are important for the applications of polymer eyeglasses lenses. In this study, the high-refractive index polymer lenses, n=1.67, were fabricated by injection-molded method with the xylene diisocyanate monomer, 2,3-bis-1-propanethiol monomer, and benzotriazol UV absorber (SEESORB 709) mixture. To reduce the reflection of the polymer lens surfaces, multi-layer anti-reflection (AR) coatings were coated for both sides of the polymer lens using an E-beam evaporation system. The optical properties of the UV blocking polymer lens were characterized using a UV-visible spectrometer. The material properties of the thin films, which were composed AR coating layers, refractive index, and surface roughness, were analyzed by ellipsometry and atomic force microscopy. As a result, the fabricated polymer lens perfectly blocked ultra-violet rays below 395 nm with a blocking rate greater than 99%.

• Journal of Convergence for Information Technology
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• v.8 no.1
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• pp.147-152
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• 2018

A polarizing spectacle lens having a perfect blocking of ultraviolet light and a partial blocking of blue light and having photochromic properties has been developed. It is a functional spectacle lens which can be used as a spectacle lens in the daytime, which plays a role of sunglass in a space with strong ultraviolet rays, dramatically reducing glare caused by late-night driving or reflected light. Photochromism was recovered in 0.5 second dark reaction and 3 seconds recovery time. The polarization function was about 95%. Ultraviolet rays were completely blocked and blue light was reduced by about 30%. A lens that combines photochromic and UV blocking and polarization functions is the first attempt at investigating the domestic market.