• Journal of Korean Ophthalmic Optics Society
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• v.4 no.2
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• pp.135-140
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• 1999

To investigate the visual acuity of the women middle and high school students, the visual acuity test was performed the object and subject methods. The results were as follows; 1. The eye types were 96.7% positive for myopia, 2.5% for emmetropia, and 0.8% for hyperopia, respectively. 2. The abnormal refraction eyes were 61% positive for simple myopia, 35.2% for myopitic compound astigmatism, 3% for myopic simple astigmatism, and 0.8% for simple presbyopia, respectively. 3. The asix of astigmatism were 95% positive for irregular astigmatism axis, 3% for regular astigmatism axis, and 2% for oblique astigmatism axis, respectively. 4. On the total myopic spheric power, the -0.50

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.125-129
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• 2000

To fine understand the visual acuity of female old age. This study was researched the visual acuity test by the object and subject methods. The major findings was as follows: 1. The eye types were 80.94% positive for hyperopia. 13.86% for myopia and 5.19% for emmetropia respectively. 2. The anbormal refraction eye was positive for mixed astigmatism for 78.27%, myoptic com pound astigmatism (10.99%), simple presbyopia(4.97%), myopic simple astigmatism(2.88%), presbyopia compound astigmatism (1.57%), simple myopia(0.78%) and presbyopia simple astigmatism(0.52%). 3. The axis of astigmatism was 60.23% for against regular astigmatism. 22.73% for oblique astigmatism and 17.05% for regular astigmatism respectively. 4. On the total myopic spheric power, the -0.50 spheric equivalent ${\leq}-2.00$ was 90.2%, the -2.00${\leq}-6.00$ was 9.8%. 5. On the total presbyopic spheric power, the -0.50${\leq}-2.00$ was 80.252%, the -2.00${\leq}-6.00$ was 16.99% and 2.56% for anything over the 6.00 diopter. 6. On the astigmatic power, the $0.50{\geq}$ cylinder power${\geq}1.00$ was 69.35%,the 1.00> cylinder power ${\geq}2.00$ was 27.38%, and anything over the 2.00 cylinder diopter was 3.27%.

• 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.4 no.1
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• pp.77-82
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• 1999

To have a fine understand the refractive error eye of Korean adult male, This study was researched visual acuity test using objuctive and subjective methods. The results are as follows: 1. The eye types were 93.3% positive for myopia, 5.4% for emmetropia, and 1.7 forhyperopia, respectively. 2. The refractive error eye was positive for compound myoptic astigmatism for a percntage of 62.6%, simple myopia(32.4%), simple myoptic astigmatism(1.6%), simple hyperopia(l.4%) simple hyperopia astigmatism(0.5%), and mixed astigmatism(1.6%). 3. The axis of astigmatism was 59.7% for regular astigmatism, 25.3% for oblique astigmatism, and 15% for reverse regular astigmatism, respectively. 4. on the total myoptic spheric power, the -2.00

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.383-387
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• 2014

Purpose: To investigate the effect of corneal unique shape to changes of refractive full corrections when pupil size changes. Methods: Subjective refraction for monocular full correction was performed to 30 subjects ($23.33{\pm}1.78$ of age, 60 eyes) in two room conditions, 760 lx and 2 lx, respectively. Pupillary diameter was measured in two conditions and the change pattern was analyzed using a peak data of corneal topography. Results: Pupillary diameter was 3.74~4.00 mm in 760 lx and 5.52~5.90 mm in 2 lx. By comparison with refractive data in 760 lx, those data in 2 lx was changed as follows: more (-) spherical power of 17 eyes (28.3%), more (+) spherical power of 10 eyes (17.7%), more (-) cylinderical power of 17 eyes (28.8%), less (-) cylinderical power of 9 eyes (15.3%), and astigmatic axis rotation of 36 eyes (62.1%). From peak data of corneal topography, the changing pattern of two principal meridians was classified into 4 types. Conclusions: Expansion of the corneal refractive surface accompanied with pupillary dilation may be a main factor that effects the changing a values of subjective refraction because of unique corneal shape. Therefore, subjective refraction should be performed under the nearest lighting condition to a main living environment.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.49-53
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• 2001

To investigate the visual acuity of the primary school children. the visual acuity test wan performed the object and subject method. The results were follows. 1. The eye types were 94.8% positive for myopia, 1.2% for emmetropia and 4.0% hyperopia, respectively. 2. The abnormal refraction eyes were 71.3% positive for simple myopia, 17.9% for myopic compound astigmatism, 6.9% for myopic simple astigmatism, and 2.5% for simple hyperopia, 0.6%for hyperopic compound astigmatism, 0.8%for hyperopic simple astigmatism, respectively. 3. The axis of astigmatism were 72.8% for astigmatism with-the-rule, 23.2% for astigmatism against-the-rule, 4.0% for astigmatism oblique, respectively. 4. On the total myopic spheric power, the -0.50

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.3
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• pp.219-225
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• 2010

Purpose: Usefulness in predicting the power of spherical rigid gas-pearmeable (RGP) lenses prescription using dioptric power matrices and arithmetic calculations was evaluated in this study. Noncycloplegic refractive errors and over-refractions were performed on 110 eyes of 55 subjects (36 males and 19 females, aged $24.60{\pm}1.55$years) in twenties objectively with an auto-refractometer (with keratometer) and subjectively. Tear lenses were calculated from keratometric readings and base curves of RGP lenses, and the power of RGP lenses were computed by a dioptric power matrix and an arithmetic calculation from the manifest refraction and the tear lens, and were compared with those by over-refractions in terms of spherical (Sph), spherical quivalent (SE) and astigmatic power. Results: The mean difference (MD) and 95% limits of agreement (LOA=$MD{\pm}1.96SD$) were better for SE (0.26D, $0.26{\pm}0.70D$) than for Sph (0.61D, $0.61{\pm}0.86D$). The mean difference and agreement of the cylindrical power between matrix and arithmetic calculation (-0.13D, $-0.13{\pm}0.53D$) were better than between the others (-0.24D, $0.24{\pm}0.84D$ between matrix and over-refraction; -0.12D, $0.12{\pm}1.00D$ between arithmetic calculation and over-refraction). The fitness of spherical RGP lenses were 54.5% for matrix, 66.4% for arithmetic calculation and 91.8% for over-refraction. Arithmetic calculation was close to the over-refraction. Conclusions: In predicting indications and powers of spherical RGP lens fitting, although there are the differences of axis between total (spectacle) astigmatism and corneal astigmatism, Spherical equivalent using an arithmetic calculation provides a more useful application than using a dioptric power matrix.