• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.373-383
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• 2013

Purpose: In this study, we analyzed refractive power of school children in low income family. Methods: We have done a comparative analysis with 112 subjects of low-income of 17 elementary schools in the Yeongcheon area and low-income children less than -6 D of refractive errors from the Korean National Health and Nutrition Examination Survey Report 2010. Results: Spherical equivalent (SE) with low-income group of nation was -1.99 D for right eye and -1.81 D for left eye, while high income group of nation showed -1.26 D and -1.21 D for right eye and left eye respectively. The SE with low income group in Yeongcheon area was -1.85 D for right eye and -1.81 D for left eye. The SE with orphan was -2.75 D and -2.42 D. Single parent family was -2.10 D and -1.96 D, and two parent family was -1.75 D and -1.73. Conclusions: The lack of attention to children eye care may be one of cause for myopia, so the role of the parents and teacher is very important. However, limited role of parents to children due to low income, it is necessary to provide an institutional strategy and social interest to prevent children vision' in low income family.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.2
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• pp.167-170
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• 2011

Purpose: This study was tried whether expectation of astigmatism from spherical equivalent visual acuity was possible. Methods: For 54 men and women (108 eyes) corrected to emmetropia, average age of 23.3, changes of visual acuity (5m) were measured with an increasing the powers at every ${\pm}$0.25D when the (-) axis of cross cylinder is $180^{\circ}$, $90^{\circ}$, and $45^{\circ}$, respectively. Results: As the power of cross cylinder was increased, visual acuity was decreased. When the powers of cross cylinder were ${\pm}$2.50D ($180^{\circ}$ and $90^{\circ}$) and ${\pm}$2.25D ($45^{\circ}$), visual acuity was 0.05 which is the minimum measurement possible. Conclusions: The diagram on astigmatism dealing with each spherical equivalent visual acuity was able to tabulate.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.39-45
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• 2009

Purpose: The purpose of this study is to compare the visual performance by contrast sensitivity (CS) and disability glare (DG) in low astigmatic eyes corrected with toric soft lenses and other optical corrections. Methods: Twenty university students with myopia (-1.00 to -6.50D Sph. with astigmatism up to 1.50 cyl) were enrolled and corrected by five different methods: 1) soft toric lenses; 2) spherical soft contact lenses; 3) RGP lenses; 4) best spectacle corrected visual acuity; 5) spherical equivalent spectacles. All subjects had corrected vision acuity of 20/20 or better. Contrast sensitivity and disability glare were measured using the OPTEC 6500 contrast sensitivity view-in tester included the EyeView Functional Vision Analysis software at photopic or mesopic conditions with glare. Results: At photopic condition, best corrected spectacle wearers had the highest monocular contrast sensitivity at all spatial frequency followed by soft toric lenses, RGP lenses, spherical equivalent spectacles, and spherical soft contact lenses. However, all of them were in normal contrast sensitivity value at photopic condition. At mesopic condition with glare, toric soft lenses were the highest and followed by RGP lenses, spherical equivalent spectacles, best spectacle corrected visual acuity and spherical soft contact lenses. It was observed that spherical soft contact lens wearers demonstrated lower range than normal contrast sensitivity value at mesopic condition with glare. Conclusion: Toric soft lenses gave better visual performance than spherical soft lenses in low astigmatic eyes. Subjects requiring the use of contact lenses under mesophic conditions could benefit from toric soft lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.87-92
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• 1998

Unaided visual acuity was tested by ACP-7 TOPCON chart projector on 376 kindergarteners and objective refraction error was measured by NIDEK ARK-700A auto-refractokeratometer on 554 eyes aged 3 to 5. The results were as follows ; The average unaided visual acuity of children aged 3 was 0.82, aged 4 was 0.90 and aged 5 was 0.92 respectively theerfore children s visual acuity has been gradually developed with their age. The kind of refractive error was 1% for hyperopia, 14% for hyperopic astigmatism, 3% for myopia, 50% for myopic astigmatism, 18% for mixed astigmatism and 14% for emmetropia respectively.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.113-117
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• 2008

Purpose: This study is to survey that uncomfortable feeling of visual acuity in the first wearing glasses, the number of visiting in age, above vision ranging and refractive errors, astigmatism, and anisometropia. Methods: Automatic refraction and naked visual acuity test executed to receive prescription glasses that the man 509 and women's 499 people visited for the first time, among 3~15 years old who visited an ophthalmoiogical hospital, from January to December, 2003. Results: The first wearing glasses started 3 years old and the most cases was 8~9 years old when they were visited visual acuity 0.5 to 0.7 in most cases. Refractive errors appeared 8 years old and its most plentifully with 20.4%, 92.2% was myopia and 5.2% was hyperopia for the man. Also cases of women was 91.9% for myopia and 5.1% for the hyperopia. Spherical equivalent power was S-1.50${\pm}$1.10D and appeared 62.3% for the low myopia. Astigmatism was appeared 44.6% for the with the rule astigmatism and 75% was cylinder power lower than 1.00D. Cases of simple astigmatism need to glass when was cylinder power C-1.37${\pm}$1.01D, and C-0.50D appeared most distribution. More than 2.00D anisometropia appeared 2.3% for the whole subjective. Conclusions: Of the first wearing glasses visual acuity is 0.5~0.7, spherical equivalent power is S-1.50${\pm}$1.10D, cylinder power of simple astigmatism is C-1.37${\pm}$1.01D.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.4
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• pp.419-424
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• 2012

Purpose: We were to obtain the basic data for studying kinetic visual acuity through the comparative analysis in kinetic visual acuity, visual acuity, refractive error, pupil size, and hand reaction time for college students. Methods: We had tested the kinetic visual acuity, visual acuity, refractive error and hand reaction time using the kinetic visual acuity tester (KOWA AS-4A), the hand reaction time program and auto-refractometer for thirty-nine male and same female optometry students with more than +0.1 LogMAR visual acuity in both eyes. And the results were examined gender differences of kinetic visual acuity and the factors correlation. Results: In the measured values of male, pupil size were 6.00 mm, hand reaction time 0.23 msec, refractive error -1.66 D, visual acuity -0.07, kinetic visual acuity 0.59 and pupil size 5.86 mm, hand reaction time 0.24 msec, refractive error -2.08 D, visual acuity -0.02, kinetic visual acuity 0.46 in female. It was significant difference for kinetic visual acuity values but other factors were not. The kinetic visual acuity and left visual acuity had the highest correlation, r=-0.406. The kinetic visual acuity indicated more excellent values in the case of increasing visual acuity and decreasing myopia amount. Conclusions: It was able to see that male college students were better than female for kinetic visual acuity and the visual acuity were related to kinetic visual acuity.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.4
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• pp.501-509
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• 2015

Purpose: To evaluate the reliability of refractive power by comparing the marked refractive power in an automatic phoropter and actually measured spherical/cylindrical refractive power. Methods: Actual refractive power of minus spherical lens and cylindrical lens in an automatic phoropter was measured by a manual lensmeter and compared with the accuracy of marked refractive power. Furthermore, combined refractive power and spherical equivalent refractive power of two overlapped lenses were compared and evaluated with the refractive power of trial lens. Results: An error of 0.125 D and more against the marked degree was observed in 70.6% of spherical refractive power of spherical lens which is built in phoropter, and the higher error was shown with increasing refractive power. Single cylindrical refractive power of cylindrical lens is almost equivalent to the marked degree. Combined spherical refractive power was equivalent to spherical refractive power of single lens when spherical lens and cylindrical lens were overlapped in a phoropter. Thus, there was no change in spherical refractive power by lens overlapping. However, there was a great difference, which suggest the effect induced by overlapping between cylindrical refractive power and the marked degree when spherical lens and cylindrical lens were overlapped. Spherical equivalent refractive power measured by using a phoropter was lower than that estimated by trial glasses frame and marked degree. The difference was bigger with higher refractive power. Conclusions: When assessment of visual acuity is made by using an automatic phoropter for high myopes or myopic astigmatism, some difference against the marked degree may be produced and they may be overcorrected which suggests that improvement is required.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.1
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• pp.35-40
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• 2005

Subjective and objective visions were measured on young adults(mean 21 yrs, 126 eyes) who were free of any ocular diseases and laser surgery and none wore contact lenses. The aim of this study was to investigate the diurnal variation of vision through subjective and objective measurements. Subjective visual acuity were measured at 5 m three times a day, morning(8:00 AM-10:00 AM), noon(12:00 PM-2:00 PM) and afternoon(4:00 PM-6:00 PM). The instrument used for objective refraction right after visual acuity measurement was Nvision-K 5001(shin-nippon) which unique in being able to disregard subject's accommodation because of its unrestricted viewing conditions. Also, we measured that three times and then calculated the average values. The result showed that an average subjective visual acuity in the morning, noon, afternoon were 0.256(${\pm}0.263$), 0.266(${\pm}0.276$), 0.242(${\pm}0.249$) respectively. Average spherical equivalent power in objective refraction of right eyes showed -3.416 D(${\pm}2.907$), -3.359 D(${\pm}2.735$), -3.297 D(${\pm}2.709$) respectively and dioptric power was decreased from morning to afternoon. Vision changed throughout the day in both subjective and objective measurements nevertheless its variations were statistically insignificant(p<0.05). Therefore it does not seem to matter of time for either visual acuity test or refraction.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.4
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• pp.425-431
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• 2011

Purpose: For better understanding refractive error in Korean children and teenagers, a follow-up study on the changes of refractive error was performed in 1~13-year-old subjects for ten years. Methods: Among the people who had visited an ophthalmologic hospital in Seoul to examine the visual acuity and to correct refractive error from 2000 to 2010 years, 223 subjects (364 eyes) having the corrected visual acuity over 0.7 had been investigated the changes of spherical equivalent power of the cycloplegic clinical refraction and manifest clinical refraction from the accumulated medical record data for ten years. Results: The changes of spherical equivalent power for ten years in 1 to 13 years old were shown the highest change at 7-year-old. And annual change of spherical equivalent power was shown the highest change at from 9-year-old to 10-year-old (-0.64${\pm}$0.64 D) followed by from 8-year-old to 9-year-old (-0.64${\pm}$0.81 D). Conclusions: The changes of refractive error for Korean children and teenagers aged 1 to 13 years in an optometric practice were shown the tendency to proceeding to myopia with age, especially the largest increase at from 7-year-old to 10-year-old, and this period is important for vision care.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.3
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• pp.329-339
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• 2013

Purpose: In this study, nutrient intake during the adolescent period is a critical time for the development of the vision. Therefore we analyzed the relationship between the obesity index and the refractive power. Methods: We used the Korean National Health and Nutrition Examination Survey 2010 document. The obesity index is classified as Broca index (less than 80.0% is low weight, 80 to 89.9% is underweight, 90.0 to 109.9% is normal, overweight is from 110.0 to 119.9%, 120.0% or more is obesity) and body mass index (BMI)(less than 18.5 is underweight, 18.6~22.9 is normal, 23.0 to 24.9 is overweight, and obesity is higher than 25.0). We analyzed correlation with the body mass index and refractive error in adolescent. Results: As shown in the statistics, according to Broca index and body mass index (BMI), the refractive power and the obesity index showed a statistically significant correlation in the ages 15 to 18. Under weight subjects are ingested 43.84% dietary fiber, vitamin C 56.55%, 35.20% iron, 31.84% of, and 38.03% potassium less than the average food intake by the standard group. Conclusions: Moderate weight with a broad variety of taking nutrition and good eating habits seems to have an effect to the good growth and the good vision.