• Journal of Korean Ophthalmic Optics Society
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• v.2 no.1
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• pp.77-83
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• 1997

This study was carried out to investigate the effect of environmental factors on 380 children's unaided visual acuity and to determine the visual acuity and objective refraction error of these children. The unaided visual acuity and objective refraction error were measured by the TOPCON chart projector and refractometer on 147 kindergarteners and 233 primary school children ranging from age 5 to 12. The measurement on the unaided visual acuity of children were 3% for below the 0.1 visual acuity 9% for 0.1~0.4. 18% for 0.5~0.7. 16% for 0.8~0.9. and 54% for over 1.0 visual acuity respectively. The refractive errors were 9.35% for mixed astigmatism. 14.5% for hyperopia 75.88% for myopia. and 0.27% for emmetropia. respectively. When analyzing the environmental factors. the relationship between the children's visual acuity and the number of hours the children watched TV. the more hours they watched TV. the more the children lost their visual acuity. The visual acuity of children decreased abruptly in the groups that watched TV more than 4 hour a day. When comparing the relationship between the children's visual acuity and proximity to the TV, the further away from the TV they were the higher visual acuity. There is rna relation between the children's visual acuity and the studying hour or reading hour of children. The relationship between the children's visual acuity and their dwelling environment, the visual acuity of children who lived in an independent house were better than the visual acuity of children who dwelled in an apartment.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.2
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• pp.173-178
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• 2013

Purpose: This study is to predict refractive errors according to uncorrected visual acuity using uncorrected visual acuity of the first glasses wearers. Methods: For 886 children who visited an ophthalmic clinic, subjective refraction was carried out with maintain refraction (MR) and cycloplegic refraction (CR), and objective refraction was carried out using auto-refractometer. Uncorrected visual acuity and corrected visual acuity were tested using on a trial lens and a Han's visual acuity chart. Results: In correlation between with the uncorrected visual acuity and refractive the myopia was the highest (r=0.774) and followed by hyperopia (r=0.670), simple astigmatism (r=0.623), simple with-the-rule astigmatism (r=0.604)and simple against-the-rule astigmatism (r=0.508). Conclusions: There were differences in the predictions between uncorrected visual acuity and refractive error according to the types of refractive error and astigmatism.

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.2
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• pp.87-90
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• 1999

After we compared the Unaided visual acuity and the Corrected visual acuity who were wearing eyeglasses, over second grade of elementary school in Chonju and Iksan, we could get conclusions like these. 1. The grades are getting higher, there are more who are wearing eyeglasses. 2. Unaided visual acuity becomes worse but and Corrected visual acuity becomes better according to older. 3. There are 23 eye, (17.8%) in boys and 38 eye, (19.2%) in girls who have below 0.6 of the Corrected visual acuity who have to change their eyeglasses. 4. If Unaided visual acuity is getting better, Corrected visual acuity is betre. 5. There were 4 boys (6.2%) and 9 girls (9%) is Anisometropia.

• 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.7 no.2
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• pp.217-221
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• 2002

After we compared the Unaided visual acuity and the Corrected visual acuity who were wearing spectacles, all over elementary school in Iksan, we could get conclusions like these. 1. The grades are getting higher, there are more who are 0.6 unaided visual acuity, and getting higher Corrected who were wearing spectacles. 2. There are 30% who have to change their wearing spectacles. 3. Higher grade separated into good or worth visual acuity then lower grade. 4. When the first grade grow up third grade, change of unaided visual acuity increased at 0.2, decreased 0.7 and 1.0, but the case of fourth grade becomes sixth grade shown a little changes unaided visual acuity.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.95-99
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• 2007

This study performed apreliminary test with male high school students in Gwangju metropolitan city in order to determine visual function information of high school students. For the items in this preliminary test, there were inquiry, test for long distance unaided visual acuity, pinhole visual acuity test, colour vision test, cover test and stereo test. Most complaint related to eye was about blurred vision (28.4%) and over 90% of subjects had one or more, and among them, over 50% appealed two or more complaints. 76.1% of all subjects showed less than 0.7 in unaided distance visual acuity. In pinhole visual acuity test, 98% had an improved unaided pinhole visual acuity and most of them experienced an improvement and 2% had no change or dropped. The students with normal stereoscopic vision test were 85.6% and the students under normal range were 14.4%. In colour vision test, 7.9% of them were protanomaly and deuteranomaly and none of them had trichromasy and total color blindness. In cover test, it showed 30.2% of orthophoria, 8.2% of esophoria and 61.5% of exophoria, and none of them had strabismus.

• 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.2 no.1
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• pp.149-154
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• 1997

We investigated the dominant eye of 123 Korean over twenty years old, then examined the refractive correlation of dominant eye, the unaided visual acuity and over-correlation. The results of these investigations are following. 91 persons of the whole number, 74%, have the dominant eye of right. The refractive correlation to the glasses are the high dominant eye. There are many men who are the same in unaided visual acuity. In men, they prefer to have the non-dominant eye but in women, they like better to have the dominant eye. The unaided visual acuity of ametropia, however, prefer to have the non-dominant eye in both men and women. In case of over-correction of an eye, there was affected the response of the other eye over 50% at the same time and the case of over-correction of dominant eye has more number than that of non-dominant eye.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.2
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• pp.137-146
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• 2016

Purpose: The relationship between retinal conditions such as macular thickness and retinal volume of the eyes with central serous chorioretinopathy(CSC) and visual acuity was investigated. Methods: A total of 136 eyes from 78 subjects was divided into 5 groups: CSC eyes under treatment and its asymptomatic contralateral eyes, fully cured CSC eyes after the diagnosis and its contralateral, and normal eyes. Their uncorrected visual acuity(UCVA), best corrected visual acuity(BCVA), retinal thickness and retinal volume were further examined. Results: All of UCVA, BCVA, retinal thickness and retinal volume of CSC eyes under treatment were significantly different from those of asymptomatic contralateral eyes, fully cured CSC eyes and normal eyes. BCVA of the asymptomatic contralateral eyes was not significantly different from it of normal eyes, however, its retinal thickness and volume were significantly different from those of normal eyes. Increased degree of retinal volume along with the increase of retinal volume was greater in CSC eyes and its asymptomatic contralateral eyes, fully cured CSC eyes and its contralateral eyes than normal eyes. Conclusions: From the present study, it was revealed that the retinal thickness and volume of asymptomatic contralateral eyes of CSC increase as well as CSC eyes, and the change of BCVA due to CSC occurs only when the retinal thickness and volume increase in some extent.

• Journal of Korean Ophthalmic Optics Society
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• v.2 no.1
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• pp.61-76
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• 1997

In this paper, we found out the objective refractive errors, the full corrective refractive powers, and the prescriptions for 64 males and 36 females aged 18 to 26 years. To increase the unaided visual acuity 0.1 to the aided visual acuity 1.0 with the glasses, we needed the spherical equivalent refractive power of -3.00D for male and -2.91D for female respectively. To increase the unaided visual acuity 0.5 to the aided visual acuity 1.0 with the glasses, we needed the spherical equivalent refractive power of -0.5D for male and -1.38D for female respectively. Comparing unaided visual acuity and corrective refractive power, the more one has refractive error the less one has unaided visual acuity but these are not linear relationships. Comparing objective refractive error figures, full corrective refractive power figures and prescriptions, objective refractive error figures are the hightest, followed by full corrective refractive power figures. Prescriptions compared with the other two are lower. The cylindrical refractive powers are less than -2.50D. In this study, with the rule astigmatism is dominant over against the rule astigmatism and oblique astigmatism. The accommodation measured by push up method is 6.75D~10.04D for male and 7.50D~9.60D for female respectively.