• Journal of Korean Ophthalmic Optics Society
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• v.21 no.2
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• pp.119-126
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• 2016

Purpose: To analyze the effect of accommodative control and change values between subjective refraction (SR) and auto-refraction (AR) according to application of fogging after accommodative stimulation depending on ametropia type. Methods: Myopic ametropia 76 eyes and hyperopic ametropia 52 eyes participated for this study. SR and AR values measured by three test conditions (Before accommodative stimulation; Before AS, After accommodative stimulation; After AS, and After application of fogging; After AF) were compared, respectively. Results: In myopic eyes, (-)spherical power by SR and AR in After AS test was significantly increased as compared to Before AS test, (-)spherical power in After AF test was decreased to the level of Before AS test. The differences of spherical power between SR and AR were highly measured by SR in After AS test, and highly measured by AR in After AF test, respectively. In hyperopic eyes, (+)spherical power of SR significantly decreased in After AS test compared to Before AS test, more (+)spherical power was detected in After AF test compared to Before AS test. (+)spherical power of AR have no significant difference between Before AS and After AS test, but more (+)spherical power was detected in After AF test compared to Before AS test. The differences of (+)spherical power between SR and AR were significant in all test conditions. Among 52 eyes which were measured as hyperopic ametropia, 7 eyes were measured as myopia by SR in After AS test. In case of AR, 25 eyes among 52 eyes were mismeasured as myopia of ranges from -0.25 D to -1.25 D in Before AS test, 26 eyes in After AS test, and 19 eyes in After AF test were mismeasured as myopia of ranges from -0.25 D to -1.25 D. Conclusions: Regardless of ametropia type, accommodative control by After AF test was effective on both refraction process. However, in auto-refraction for hyperopic eyes, the misdetermined proportion of refractive error's type was high due to consistent accommodative intervention in all test condition. Therefore, in order to obtain an accurate value of refractive errors, full correction should be determined by subjective refraction process after fogging method.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.2
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• pp.239-246
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• 2014

Purpose: This study was performed to investigate the effect of induced ametropia on static posture for body balance. Methods: Twenty subjects (10 males, 10 females) of average age $23.4{pm}2.70$ years were participated and ametropia(binocular myopia; BM, simple myopic anisometropia; SMA, binocular hyperopia; BH, and simple hyperopic anisometropia; SHA) were induced with ${pm}0.50D$, ${\pm}1.00D$, ${\pm}1.50D$, ${\pm}2.00D$, ${\pm}3.00D$, ${\pm}4.00D$, ${\pm}5.00D$, respectively. General stability (ST), weight distribution index (WDI), and fall risk index (FI) were measured using TETRAX the biofeedback systems. Each index of the body balance was evaluated for 32 seconds in each ametropic condition and those value was compared with the value in fully corrected condition. Results: The ST showed significant increase from +0.50 D under condition of BM, from +1.00 D under condition of SMA, from -1.00 D under condition of BH, and from -1.50 D under condition of SHA compared with under condition of fully corrected condition, respectively. The FI showed significant increases from +4.00 D under condition of BM, from -1.00 D under condition of BH, and from -1.50 D under condition of SHA. The WDI show no change in all ametropia condition. Conclusions: Whatever ametropia is, uncorrected refractive error could reduce the general stability of body balance and increase the falling risk.

• 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.6 no.2
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• pp.81-84
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• 2001

This study can provide the accurate information on the treatment of visual acuity of a old ages by test of eye refraction state. The test was performed the visual acuity test by the object methods, and subjects was the over 45 old age. The eye types were 12% positive for emmetropia, 19% for myopia. and 69% for hyperopia, respectively. The abnormal refraction eyes were 3% positive for simple myopic astigmatism, 16% for myopic astigmatism, 14% for simple hyperopia, 5% for simple hyperopic astigmatism, 62% for mixed astigmatism, respectively. The axis of astigmatisms were 72% positive for against-the-rule astigmatism, 21% for with-the-rule astigmatism, 7% for ablique astigmatism, respectively.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.105-110
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• 2007

To investigate the ametropia and refractive error of 222 ametropic eyes of the 111 high school students in Gwangju Metropolitan City, the visual acuity test was performed by the object and subject method. 85% of the eye types were positive for myopia, 14% for emmetropia, and 1% for hyperopia, respectively. 38% of the abnormal refraction eyes were positive for simple myopia, 4% for myopia simple astigmatism, 56% for myopia compound astigmatism, and 0% for simple hyperopia, 0% for hyperopia simple astigmatism, 2% for hyperopia compound astigmatism, 0% for mixed astigmatism, respectively. 92% of the axes fo astigmatism were for astigmatism with-the-rule, 6% for astigmatism against-the rule, 2% for astigmatism oblique, respectively. As for the astigmatic power, 0.50 < cylinder < 1.00D was 68%, 1.00 < cylinder < 2.00D was 25%, and anything over the 2.00 cylinder D was 7%. As for the equivalent spheric power of myopic abnormal refraction eyes, -0.50 < spheric equivalent < -2.00D was 26%, -2.00D < spheric equivalent < -6.00D was 55% and anything over the -6.00D was 19%. The rate of wearing glasses was 74%. It increases compared to 20 years ago. 91% of the eye test place was the optical shop, 9% the eye doctor hospital. 80% of the students need to change their optical lenses because spherical equivalent power was over 0.50D.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.65-69
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• 2001

To investigate the visual acuity of the primary school children. This study was researched visual acuity test using objective and subjective methods. 1. The eye types were 90.3% positive for myopia, 3.1% for emmetropia, 4.9% hyperopia, 1.7% for mired astigmatism. 2. The abnormal refraction eyes were 58.6% positive for simple myopia, 29.9% for myopic compound astigmatism, 5.1% for my optic simple astigmatism and 1.9% for simple hyperopia, 1.9% for hyperopic compound astigmatism, 1.3% for hyperopic simple astigmatism, 1.3% for mixed astigmatism. 3. The axis of astigmatism were 85.7% for astigmatism with-the-rule, 9.3% for astigmatism against-the-rule, 5.0% for astigmatism oblique. 4. On total myopic spheric power. the -0.50

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.4
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• pp.345-350
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• 2006

The study of the visual acuity and refraction status was performed to the students of primary school using eyeglasses in Kyung Nam region, Korea. Two hundred sixty three subjects with various styles of ametropia were analyzed the visual acuity and refraction examination by the subjective and objective tools. The results of study were as follows; 1) According to the increase of age of subjects, the visual acuity of binocular in naked eyes was decrease. However ametropia was increase. 2) The high frequency of ametropia types in the binocular was simple myopia, and the next order of high frequency was mixed astigmatism, myopic compound astigmatism, simple hyperopia, and hyperopic compound, respectively. 3) On the power of spherical refractive error of ametropia, the high frequency was -1.00 diopter, and the next order of high frequency was -2.00 diopter, +2.00 diopter, -3.00 diopter, and so on, respectively. 4) According to the increase of subjects ages, the changes of dioptric power of myopic spheric power was increase. however the frequency of the boy and girl was similar results, also the dioptric values of refractive status in binocular was similar results. As the results of this study, we conclude that the relationship of the visual acuity and refractive error status in primary students using eyeglasses was improved.

• Journal of Korean Ophthalmic Optics Society
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• v.2 no.1
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• pp.133-143
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• 1997

A population-based study of people aged above 20 years showed that 32% had emmetropia and 68% had ammetropia(myopia 56.6%. hyperopia 11.4%) city in Korea. The percentage of ammetropia in population based study is higher than that of clinic(O.P.D.) based. A 83.3% of the ammetropia had myopia. which is higher than 76.3% of 1968 and 76.9% of 1975 years. A 16.7% of the ammetropia had hyperopia. which is lower than 19.4% of 1968 and 17.3% of 1975 years. In the kind of refractive error. 32.1% of 985 eyes examined had compound myopic astigmatism. 18.2% had simple myopic astigmatism. 14.2% had simple myopia. 6.8% had simple hyperopic astigmatism, 5.0% had mixed astigmatism, 4.7% had compound hyperopic astigmatism and 3.6% had simple hyperopia. In the difference of binocular refractive error, 29% had 0.50~2.00 Dptr difference and 3.6% had difference above 2.00 Dptr. In age related myopic refractive error, 76.7% of people aged 20~29 years and 74.0% of 30~39 years had myopia. It is due to overstudy for entrance into a university that the percentage of myopia is higher than that of abroad. In age related hyperopic refractive error, 2.9% of people aged 20~29 years, 0.6% of 30~39 years. 6.3% of 40~49 years, 16.0% of 50~59 years and 63.9% of 60~69 years had hyperopia. It shows that the age related hyperopic refractive error was significantly increased at aged 40~49 years. The right eye had more myopic refractive error than left eye.

• 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.