• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.119-125
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• 2007

The aim of the present study was to compare the contrast sensitivity of soft contact lens wearers, spectacle wearers or emmetropia. Seventy myopic eyes and thirty emmetropic eyes aged 19 to 26 years were collected. The myopic group included 48 eyes corrected with spectacle lenses and 22 eyes of them corrected with contact lenses, too: all had corrected vision acuity of 20/20 or better. Spatial contrast sensitivity was measured using the OPTEC 6500 contrast sensitivity view-in tester included the EyeView　 Functional Vision Analysis software at photopic or mesoopic condition. There was no significant difference in contrast sensitivity between spectacle lenses and emmetropes. Myopes corrected with soft contact lenses showed statistical sensitivity losses at 1.5, 12 cycle/degree spatial frequencies. In conclusion, our findings suggest that loss of contrast sensitivity in soft contact lens wearers might be interpreted as evidence for corneal disruption before corneal pathological events occur in contact lens wearers. Contrast sensitivity testing appears to be a useful method for evaluating soft contact lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.2
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• pp.73-78
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• 2000

The purpose of our study was investigation for the status of eye health in Taejon area. I chose the age of eight to under eighteen 61 institutional care children, and I examed the first visual acuity examination ophthalmoscopy and non-criterion interview. Among 61 institutional care children (primary school student 40.98%, secondary school student 59.01%), 56.74% children were emmetropia, 44.46% were ametropia. Unaided visual acuity 0.7, 0.8 were 37.03% of these children. As refractive errors, 31.14% were myopia. 26.23% were compound myopic astigmatism and only 1.64% institutional care children wearing the glasses. In children, early eye examination is essential for their eye health. Therefore attention to early eye examination and wearing correct glasses seem to be very important especially for institutional care children. I propose that we have to concerned about eye health and concrete plan for institutional care children.

• Journal of Korean Clinical Health Science
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• v.7 no.2
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• pp.1337-1344
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• 2019

Purpose. This study was the analyze the refractive status of presbyopia in Korea. Methods. The subjects was from November 2018 to October 2019, two hundred thirty four subjects( 117 male subjects, 117 female subjects; from 40-year old to 88-year old ) were performed in refraction test using the Auto-Refraction(Speed -K model, Japan). The myopia, hyperopia, astigmatism, and anisometropia were defined as spherical equivalent(SE)≤-0.50 diopters, SE ≥+1.00 D, cylinder error ≥0.75 D and SE difference≥1.00 D between binocular eyes, respectively. Results. The refractive status by spherical equivalent among all subjects was myopia 61.43%, astigmatism 86.86%, emmetropia 19.18%, anisometropia 12.07%, and hyperopia 18.54. The prevalence of myopia and astigmatism were much more common in male. However, The hyperopia and astigmatism were much more common in female. The prevalence of spherical equivalent was much common from -0.50 diopter to -5.00 diopter. On the other hand, the prevalence of astigmatism and myopia was much more than hyperopia in all subjects. There was a statistical significance between OD and OS of the female and male in the spherical equivalent power(p<.000). However, there was not statical significant between female and male of OD and OS in the spherical equivalent power(p<.070). On the other hand, The prevalence of againest axis in astigmatism was more common in all subjects. In ADD power for the near vision correction, the female was much more diopter than male. Conclusions. These results suggested that the analysis of the refractive status on the presbyopia in Korea can give the useful diagnosis data for the correction of visual acuity at near distance.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.61-64
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• 2008

Purpose: The analysis of individual eye model designed from clinical demonstration about emmetropia shows that the aberration would be changed by the wave change. Method: The model on the basis of clinical demonstration of eye ball is designed in a form of having 4 refraction surfaces and a constant refractive index. We analyzed designed twelve individual eye model into aberrations changes, as giving changes Fraunhofer lines's six wavelengths. Result: About individual eye model, change in the wavelength of the wavefront aberrations analysis using the Zernike coefficient. This data indicate that the shorter wave is, the more defocus increases and the deviation value of spherical aberration and RMS are widened. Conclusion: As quantity of defocus according to result wavelength change is shorter and shorter, inclination which is similar twelve individual eye model is bigger and bigger and individual eye model majority of cases, little change, and change is shown in part individual eye model is a significant performance degradation can be raised.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.187-192
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• 2006

The purpose of this research was to measurement real accmmnodative response amount of emmetropia using both eyes open-view auto-refractometer. We classified 377(male 146, female 231)eyes showing good naked vision at least 1.0, with a spherical equivalent refraction of under ${\pm}0.50D$ and cylindercal refraction of under -0.75D, from 10 to 59(mean $25.8{\pm}12.4$) years into 5 groups with 10 year interval and analyzed change of the near astigmatism and accommodative response amount to distinction of age. Age comparison, total mean 1.47D, 10 years age group 1.63D, 20 years age group 1.57D, 30 years age group 1.71D, 40 years age group 0.97D, and 50 years age group 0.05D. It was no difference between 10 to 30 years age group, But it showed the decre8.se which is remarkable from above 40 years age group and it does not almost response from above 50 years age group. Sexual difference, the man appeared some highly in male(mean $26.4{\pm}12.3$ years) 1.56D m female(mean $26.4{\pm}12.3$) 1.43D. Near-astigmatism power change, mean +0.12D, 10 years age group +0.06D, 20 years age group +0.16D, 30 years age group +0.09D, 40 years age group +0.05D, and 50 years age group +0,06D. No significant difference of astigmatism powers among the an groups, but from all years age group the astigmatism power appeared more highly far-astigmatism than near-astigmatism. Near-astigmatism axis change in the far-astigmatism changes at under ${\pm}10^{\circ}$ 103 eyes, above ${\pm}10^{\circ}$ rotation clockwise direction 108 eyes, above ${\pm}10^{\circ}$ rotation counter-clockwise direction 101 eyes. It was analyzed near-astigmatism axis change.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.103-113
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• 1998

Until now, the study of eye refractive error examination for high school students are a few report that in Korea. In particular, there is few report about the visual power for same group during several years. We compared the study of refractive error done this year with that reported three years ago at the same high school. From the these data, the distribution of ammetropia was investigated. The study of refractive error for high school students was also compared with those reported before for the Adults and the middle school student. When the visual power is refered to spherical equivalent, the 36% of the whole students examined above had emmetropia and the other part of them fumed out to be ammetropia which is classify to 60.6% belonged to myopia and 4.4% belonged to hyperpia. The ratio of myopia for this year students is increased in comparision with the students in 1995. The ratio of emmetropia for this year students is 7.4% higher, and the ratio of myopia for this year students is 4% higher, but the ratio of hyperopia is very lower than that for the adults in 1997. In the kind of refractive error, it is classified that a simple myopia is shown to highest ratio as a 28.6% of 1212 eyes examined, a compound myopic astigmatism to the next high ratio as a 22.4%, a simple myopic astigmatism as 14.4%, a simple hyperopic astigmatism as 3.1%, a mixed astigmatism as a 1.7%, a simple astigmatism as 1.2%, a compound hyperopic astigmatism as 1.2%, respectively. The percentage of an astigmatism is a 76.7% of total eyes examined if Cyl-0.25 Dptr is included to an astigmatism. On the other hand, The percentage of an astigmatism is a 45.6% of total eyes examined if Cyl-0.25 Dptr is excluded to an astigmatism. In the kind of astigmatism, the number of students had an astigmatism with the rule is about 4.5 times than that of astigmatism against the rule. From the result of comparision the right eye with the left eye, the right eye of the students had more a myopic refractive error than the left eye, which is same as adults' case, there is no difference in a refractive error between the boy students and the girl students.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.71-75
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• 2007

This research was conducted from 1 March 2005 to 28 February 2007. We collected data from optician stores around Kwang-Ju city, 208 people aged 40 to 80 years using the cross cylinder method to find out age and gender dependence of near addition. 1. Age dependence of Refractive error shows 5% of emmetropia 34% of myopia and 43% of hyperopia. These results reveal that rate of hyperopia is higher than emmetropia and myopia. Mixed Astigmatism rate was 18%. 2. Near addition required to correct Presbyopia is analyzed as functions of gender and ages. In case of man: 40-44 (+0.75D), 45-49(+1.25D), 50-54(+1.41D), 55-59(+1.92D), 60-64(+2.35D), 65-69(+1.97D), 70(+3.12D), In case of woman: 40-44 (+1.08D), 45-49 (+1.38D), 50-54 (+1.67D), 55-59(+2.05D), 60-64 (+2.50D), 65-69 (+2.57D), $70{\leq}(+3.18D)$. Result shows it's Adding power higher than man. 3. Age dependence of Axis of Astigmatism. In case of horizontal astigmatism 61.2%, vertical 2.8% and rest else for 36%. Setting point from Binocular vision tells that average adding power of 40-44 (+0.75D) or (+1.00D), 45-49 (+1.25D) or (+1.50D), 50-54 (+1.50D), 55-59 (+2.00D), 60-64 (+2.50D), 65-69 (+2.50D) or (+2.75D), over $70{\leq}(+3.00D)$ or (+3.25D) of average adding power.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.131-138
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• 2000

We compared the study of refractive error of the eyes done in 1998 with that reported three years ago at any high school in the north Kyungki. From the these data, the distribution of ammetropia was investigated. The study of refractive error for high school students was also compared with those reported before for the Adults and the middle school student. When the refractive error is refered to spherical equivalent, the 40.6% of the whole students examined above had emmetropia and the other part of them(59.4%) turned out to be ammetropia which is classified to 46.4% belonged to myopia and 13.0% belonged to hyperpia. The ratio of emmetropia for the students in 1998 is 4.4% lower, and the ratio of hyperopia is 4.3% lower, but the ratio of myopia for the students in 1998 is 8.7% higher than that for the student in 1995. In the kind of refracive error, it is classified that a simple myopia is shown to highest ratio as a 23.6% of 6143 eyes examined, a compound myopic astigmatism to the next high ratio as a 17.4%, a simple myopic astigmatism as 10.9%, a simple hyperopic astigmatism as 9.8%, a simple astigmatism as 7.1%, a compound hyperopic astigmatism as 2.2%, a mixed astigmatism as a 1.8%, respectively. The percentage of an astigmatism is a 69.6% of total eyes examined if Cyl-0.25 Dptr is included to an astigmatism. On the other hand. The percentage of an astigmatism is a 45.0% of total eyes examined if Cyl-0.25 Dptr is excluded to an astigmatism. In the kind of astigmatism, the number of students had an astigmatism with the rule is about 5.6 times than that of astigmatism against the rule. From the result of comparison the right eye with the left eye, the right eye of the students had more a myopic refractive error than the left eye, which is same as adults' case.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.67-71
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• 2002

To investigate the ametropia and refractive error of 364 ametropic eyes en the 182 high school students in Jeonbuk provicne, the visual acuity test was performed by the object and subject method. The results were as follows. 1. The eye types were 85.7% positive for myopia, 6.6% for emmetropia and 7.6% hyperopia, respectively. 2. The abnormal refraction eyes were 30.8% positive for simple myopia, 58.5% for myopia compound astigmatism, 7.5% for myopia simple astigmatism, and 1.8% for simple hyperopia, 1.3% for hyperopia compound astigmatism, 1.9% for hyperopia simple astigmatism, respectively. 3. The axes of astigmatism were 78.7% for astigmatism with-the-rule, 13.9% for astigmatism against-the-rule, 7.4% for astigmatism oblique, respectively. 4. As for the astigmatic power, the 0.50 < cylinder < 1.00dptr was 60.0%, the 1.00 < cylinder < 2.00dptr was 29.2%, and anything over the 2.00cylinder dptr was 10.8%. 5. As for the equivalent spheric power of myopic abnormal refraction eyes, the -0.50 < spheric equivalent < -2.00 diopter was 64.6%, the -2.00 < spheric equivalent < -6.00 dptr was 29.1% and anything over the -6.00 dptr was 6%. 6. The equivalent spheric power of hyperopic abnormal refraction eyes was 50% anything under 2.00diopter and 50% for anything over the 2.00diopter.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.323-328
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• 2005

The purpose of this research was to measurement real Accommodative response amount using both eyes open-view autorefractometer. Compared each Accommodative response amount to distinction of sex, age, kind of ametropia, amount of astigmatism and kind of astigmatism. The subjects were 153 healthy men and women between the age of 20~80 years. Age comparison, 20 years 1.15D, 30 years 1.23D and above 40 years 0.60D. It was no difference between 20 to 30 years old. But, is decrescent remarkably above 40 years old. Ametropia examined by hypermetropia 1.78D, emmetropia 1.51D, low myopia 1.08D, middle myopia 0.72D, high myopia 0.643D. Myopia increased, Accommodative response amount was expose that decrease. Astigmatism examined by non astigmatism 1.13D, low astigmatism 1.12D, middle astigmatism 0.85D, high astigmatism 0.83D. Astigmatism increased, Accommodative response amount was expose that decrease. The sex and astigmatism type difference appeared with the fact that the result is not a difference.