• Journal of Korean Ophthalmic Optics Society
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• v.20 no.3
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• pp.311-318
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• 2015

Purpose: This study was designed to investigate the prevalence rate of refractive error with gender and age presenting visual acuity of primary student in Jeonnam. Methods: Subjective refraction, objective refraction and visual acuity test were examined on 735 primary school children who ages of 8~13 years lived in Jenman. Presenting visual acuity test was using Han's visual acuity chart and objective refraction was carried out using auto-refractometer. Results: The presenting visual acuity was 0.1 worse in the eye of 54(7.3%) students and 49(7.3%) of them wearing the glasses. The rate of the wearing glasses were 79.3% in 0.125~0.25 visual acuity, 64.2% in 0.3~0.5 visual acuity and 61.6% in 0.6~0.8 visual acuity. It was appeared that 269(36.6%) of them were emmetropia, 321(43.7%) of them were myopia and 56(7.6%) of them were hyperopia, and 89(12.1%) of them were astigmatism. The prevalence rate of myopia was the highest and followed by the prevalence rate of astigmatism. The low degree of myopia occupied the most and the medium degree of myopia showed the tendency of increase as the students get olds. The prevalence rate of the hyperopia showed the tendency of decrease as the students get olds. The prevalence rate of with the rule astigmatism were 50.6% students and against the rule astigmatism were 48.3% of students. Conclusions: The present study reveals the considerable prevalence rates, 466(63.4%) of included subjects, of refractive errors among primary students in Jeonnam province. The rate of the wearing glasses were 313(42.6%). The prevalence of myopia increases as the students get older. Therefore students of visual management is considered necessary through the visual acuity test and refractive examination.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.2
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• pp.135-151
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• 2003

This study compared the effect of Polaroid$^{(R)}$ lenses on binocular vision by assessing visual acuity, stereopsis, and visual evoked potential(VEP), through Polaroid$^{(R)}$, CR 39 and sunglass lenses. The spectral absorptions of Polaroid$^{(R)}$, CR 39 and sunglass lenses were measured using a spectrophotometer (Hitachi. U-3501). The VEP were recorded by the Nicolet system. Thirty normal adult(fifteen males, fifteen females, mean=21.9 years, range=20 to 25) subjects were recorded. The subjects were provided a history including : general health, family health, medication, genetics, allergy and disease. All had normal or corrected to normal acuity with no history of visual disorders. Corrected visual acuity, colour vision and stereopsis were recorded for each subject monocularly and binocularly. Each test was repealed through the sunglass, CR 39, and Polaroid$^{(R)}$ lenses. Subjects viewed the VEP stimulus both monocularly and binocularly through the test lenses while the VEPs were recorded. The results suggest that the binocular visual acuity and stereoacuity is better than with monocular vision. On other hand, the analysis of VEP suggests that the amplitude of wave is smaller when the monocular eye receives the VEP stimulus compared with that when the binocular eye is stimulated by the VEP target with the sunglass, CR 39, and Polaroid$^{(R)}$ lens. But, the latency period of each eye was similar to results between the dominant eye and the non-dominant eye by the CR 39, sunglass, and polaroid lens. In conclusion, this study indicates that the binocular vision appears to be better through the brown Polaroid$^{(R)}$ lens than through the other test lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.549-554
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• 2013

Purpose: To determine the minimal illumination for visual acuity with the decimal vision chart and individual difference with varying contrast and illumination. Methods: Landolt's vision chart with 10 different grade of contrast was made. Minimal illumination was measured for 69 eyes using 100% contrast vision chart. Minimal contrast for identifying the chart was measured in conditions of the minimal illumination and 230 lx, respectively. Results: Minimal illumination was gradually increased with decrease of the chart size. Mean of minimal illumination to identify the 1.0 visual acuity was $74.39{\pm}25.90$ lx with range of 17~107 lx. In conditions of the minimal illumination and 230 lx, the minimal contrast for identifying the chart were gradually increased with decrease of the chart size in both conditions, the those deviation for 69 eyes was also increased. Conclusions: For refractive correction, examiners need to consider the individual difference for identifying the visual chart according to illumination and contrast.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.201-206
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• 2006

The purpose of this study is observed effect of cycloplegia in emmetropia with use of cycloplegia. We examined the naked visual acuity, mainfest refraction, 105eyes with emmetropia(under SE ${\pm}0.50D$, Cyl ${\pm}1.00D$) after the use of cycloplegia. We used Nidek ARK-700 autorefractometer. Sexual difference of mainfest refraction error showed in male -0.67D, female -0.92D and difference of the CR and the MR male 0.5D, female 0.81D the total mean 0.69D. The naked visual acuity were in male 0.82, female 0.74, total mean 0.77. Age comparison, difference CR and MR were total mean 0.69D and 13 years group 1.1D were the highest. The naked visual acuity were in the highest 10 years group 0.86. Effect of cycloplegia was $0.69D{\pm}0.79$ in emmetropia and visual acuity was $0.77{\pm}0.21$. The optician, it will not be able to use cycloplegia, must pay attention spectacle prescription unnecessary and over correction in condition below -0.75D MR, above 0.77 visual acuity.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.1
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• pp.41-46
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• 2005

The aim of the study was performed the wave analysis of P-VEP on the normal monocular vision and amblyopia in binocular. The P-VEP of three channels were recorded by the Nicolet system. Five adults (three males, two females, mean=22 years, range=19 to 24) subjects were recorded The subjects were researched the history including the systemic health, medication, genetics, allergy and ocular disease. Visual acuity and stereopsis were recorded for each subject monocularly and binocularly. Also subjects viewed the P-VEP stimulus both monocularly and binocularly through the corrected visual acuity during the VEP were recorded. The results of study suggest that the visual acuity of binocularly is better than with monocularly and the stereopsis was about over 140 sec. On the other hand, the analysis of P-VEP suggest that the amplitude of wave is larger when the monocular eye receives the P-VEP stimulus compared with the binocular eye. However the amplitude of wave in amblyopia had more smaller than the normal monocular The latency period of P-VEP was similar to results between the normal eye and binocular vision. But the amblyopia was a long period compared with the normal monocular and binocular vision. In conclusion, this study indicated that the visual acuity of binocularly have a better than the normal monocular vision, But in the P-VEP test, the amplitude of wave on normal monocularly vision appears to be better through the binocularly. But the amblyopia appeared the low amplitude wave of P-VEP and decreased the visual acuity.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.3
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• pp.313-317
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• 2011

Purpose: This study was to assess prevalence of refractive errors and uncorrected refractive errors in elementary school children in Mokpo and uncorrected refractive errors were to be used as the basic data. Methods: Vision tests were conducted on 400 subjects of 1st~6th grades at 3 elementary schools in Mokpo city, and subjective, objective refraction test were also performed to survey uncorrected refractive errors. Results: The prevalence of myopia was 256, 64% of total subjects, Hyperopia was 21, 5.3%, astigmatism was 19, 4.8%. The prevalence of uncorrected refractive errors were increased as higher grade and more oculus dexter higher than oculus sinister. Conclusions: Vision impairment which need an accurate vision correction for elementary school students requires the regular examination and actively correction in order to protect the elementary school students for basic welfare.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.307-312
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• 2010

Purpose: In this paper, we have dealt with problems of army supply system for eyeglasses and improvement plan. Methods: We collected the latest service request of MND (Ministry of National Defence) and case of U.S. Army and analyzed the data. Results: We treated contents, construction methods and plans for efficient use of vision DB (database) for Korean Army. We suggested several alternative proposal for eyeglasses supply system which made possible quicker delivery of eyeglasses to the soldiers and increase satisfaction. Conclusions: The Korean Army must construct vision DB to service high quality vision service to the solider. It is urgent that the Korean Army set up a unit to take charge of vision management and service. And the Korean Army need to upgrade supply system for eyeglasses.

• Therapeutic Science for Rehabilitation
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• v.7 no.2
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• pp.51-61
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• 2018

Objective: The purpose of this study was performed to modify the performance-based assessment tool, Melbourne Low-Vision ADL Index (MLVAI) had been developed in Australia to suit the Korea culture to verify the reliability and validity. Methods: The subjects were only over the age of 20 living in communities, 26 with low-vision and 42 normal persons. The Korean MLVAI was completed through the expert translation verification and validation of the configuration tool. The validity of the Korean MLVAI was established through the content, discriminant, and convergent validity. Also, the reliability was analyzed through internal consistency reliability for the items, test-retest, and interrater reliability. Results: The Content Validity Index(CVI) was more than .78. There was a statically significant low in low-vision. Also, there was a statically significant low in low-vision. The convergent validity was determined the correlation coefficient of .751 analyzing LVQOL and Korean MLVAI total score, had a significant correlation(p<.05). Cronbach's ${\alpha}$ coefficient indicated an internal consistency of .983(p<.05). Test-retest reliability had a high, significant correlation of .976 and interrater reliability had a high, an intraclass correlation coefficient of .91(p<.05). Conclusion: The results of this study mean that the Korean MLVAI which was modified to fit the Korean is the ADL assessment tool with both validity and reliability. Based on this study, the Korean MLVAI can be used as a useful ADL assessment for OT interventions in low vision.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.177-186
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• 2015

Purpose: The Purpose of this study is to investigate if the relative legibility of optotypes affects the corrected visual acuity in visual acuity test. Methods: After measuring the relative legibility of 'Landolt ring target', 'arabic number target', 'alphabet target' by showing as a single-letter-target in 24 subjects without specific ocular diseases and ocular surgery experience, the relative legibility of 0.8, 1.0, 1.25 row of vision according to type of target in 7 types of chart were compared. After then we compared by measuring the corrected visual acuity according to type of target by using binocular MPMVA test (#7A) in 60 myopic subjects. Results: In 3 types of target the worst relative legibility target was 'Landolt ring target' with legible distance of $98.97{\pm}4.57cm$ and the best relative legibility target was 'alphabet target' with legible distance of $108.42{\pm}3.46cm$. There was no difference of the relative legibility according to type of chart or visual acuity level in the row of vision if other conditions are the same. In 1.0 and 1.25 row of vision the difference of relative legibility according to type of target was shown the statistically significant difference between 'Landolt ring target' and 'alphabet target' as $-0.07{\pm}0.06$ (p=0.02) and $-0.06{\pm}0.06$ (p=0.04) respectively. In myopia the difference of corrected visual acuity according to type of target was statistically significant difference between 'Landolt ring target' and 'arabic number target' as $-0.04{\pm}0.02$ (p=0.02) and it was especially remarkable in the low myopia. Conclusions: Measuring visual acuity with different optotypes could cause the errors in best vision measurement value because there was difference of the relative legibility according to type of target even though visual acuity level is same in the row of vision.

• 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.