• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.339-345
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• 2005

In this paper, we studied the principle that correct the emmetropia to the aphakia using intraocular lens. At present, in an ophthalmic clinic, I.O.L which is using for correction of the vision clinically has presented how to prescribe more accurately by using optical method. To correct the Aphakia for the emmetropia, we considered that the basic cause of Ametropia was the refraction and the axial length. The correction principle is made equal to the Back Focal Length(BFL) and the vitreous length from lens to retina. For the confirmation of the correction principle, we used the Gullstrand number I eye model in emmetropia. For the myopia and hyperopia, we used the clinical data and replaced crystalline lens with intraocular lens.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.115-119
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• 2001

To research the refractive error of the eyes on the 30's employees, 510 eyes were tested by the object and subject methods. The results were as follows. 1. Among the 510 eyes, myopia is 74.4%, hyperopia is 0.9% and emmetropia is 24.7%, respectively. 2. In test, the low myopia (-0.50Dt < Spherical Equivalent ${\leq}$ -2.00Dt) is 24.1%, the middle myopia(-2.00Dt < Spherical Equivalent ${\leq}$ -6.00Dt) is 51.4%, the high myopia(-6.00Dt < Spherical Equivalent) is 14.8% and the low hyperopia(+0.50Dt < Spherical Equivalent ${\leq}$ +2.00Dt) is 1.2%, respectively. 3. In test of astigmatism, the amount of astigmatism with-the rule is 58.5%, the amount of astigmatism against-the rule is 22.6% and the amount of astigmatism with oblique is 18.9%, respectively.

• 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.3 no.1
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• pp.121-128
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• 1998

In this paper, We researched the optical performance of eye by means of the Gullstrand EYE MODEL. And we also researched the glasses that are made by designing the eye glasses corrected with the Astigmatism and the optical performance of the glasses in the optical system which are compounded with eyes. This paper can be used as a reference material in designing the glasses for ametropic correction.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.2
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• pp.43-48
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• 2008

This paper proposes a new method for measuring the power of spherical and cylindrical lens with 6 points light source, which is composed of a LED and six holes, and magnification ellipse fitting algorithm. Each measured diagonal length of 6 points light source is determined by the target lens power. After finding the center position of each light point with threshold method, 3 axis-diagonal lengths were calculated. The long axis and short axis power of cylindrical lens can be calculated by using magnification ellipse fitting algorithm with the magnification relationships between the initial diagonal lengths and the measured diagonal lengths changed by lens power.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.3
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• pp.247-251
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• 2013

Purpose: To analyse the addition power of new wearer of progressive addition lenses. Methods: Data of 636 subjects who have been prescribed progressive addition lenses as the first time were used for analyse. The range of age for was between 41~78 years old and they visited the optical practice in Gwangju metropolitan city from 2001 to 2013Date of refractive state, gender and age were analysed. Results: The difference of addition by gender was 1.71 D in male and 1.67 D in women. The difference of addition by refractive error was 1.67 D in emmetropic patients and 1.74 D in myopic patients, 1.90 D in hyperopic patients. The difference of addition by age was1.26 D in 41~44 years old sge group, 1.48 D in 45~49 years old age group,1.72 D in 50~54 years old age group 1.84 D in 55~59 years old age group, 2.10 D in 60~64 years old age group and 2.43 D in over 65 years old age group. The difference of addition by diopter in myopic patients was 1.58 D in low myopic patients and 1.48 D in middle myopic patients, 1.67 D in high myopic patients. The difference of addition by axis of astigmatism was 1.80 D in with-the-rule astigmatism, 1.64 D in against-the-rule astigmatism and 1.65 D in oblique astigmatism. Conclusions: The Addition power of progressive lenses were different according to the types of refractive error, astigmatism axis and age.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.41-45
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• 2002

To study the ametropia and the sort of glasses, especially progressive multifocal lens, for near purpose on Middle aged & Manhood. 500 adults were tested by the object and subject methods. Among the 500 adults, myopia is 22.4%, hyperopia is 61.4%, and emmetropia is 16.2%, respectively. In test of astigmatism, the amount of astigmatism for the age of forty one to under forty five with-the rule is 28%, the amount of astigmatism against-the rule is 43% and the amount of astigmatism with oblique is 11%, respectively. Whereas, the amount of astigmatism for the age of fifty six to under sixty with-the rule is 10%, the amount of astigmatism against-the rule is 71% and the amount of astigmatism with oblique is 19%, respectively. With-the-rule decreased with increasing age while against-the-rule increased with increasing age. The oblique astigmatism relationship to age could not be determined. The ratio of the progressive multifocal lens was 67.3% for male and 35% for female.

• Journal of the Korea Convergence Society
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• v.9 no.12
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• pp.273-279
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• 2018

This study researched how the refraction error and illumination influence to contrast sensitivity when we wear the circle contact lenses. The study population comprised 16 students and adults(5 of Male, 11 of Female). The study population comprised 16 students and adults(5 of Male, 11 of Female), We measured the contrast sensitivity on uncorrected vision, according to color of circle contact and change the illumination of laboratory. The contrast sensitivity by illumination decreased than unaided vision when they wore the color contact lenses and more increased mesopic than photopic. Compared between black and brown lenses, brown was higher the contrast sensitivity than black. Also emmetropia had significantly differences when we compared the contrast sensitivity of subjects who had emmetropia, myopia and myopia astigmatism whether refractive error has or not. Therefore, it is important to provide sufficient understanding and recognition of color contact lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.77-81
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• 2008

Purpose: This study was to investigate the refractive state of an asian population (male: 39, female: 53) from 21 to 30 years old who visited the A optical shop at jongnogu in seoul. Methods: The visual acuity test was performed by the object and subject method. Results: Among the 184 eyes, myopia is 83.16% and emmetropia is 16.84%, respectively. As for the equivalent spheric power of myopic abnormal refractive eyes, the -m0.5Dt < spheric equivalent ${\leq}$ -2.00Dt was 40.53%, the -2.00Dt < spheric equivalent ${\leq}$ -6.00Dt was 51.63% and anything over the -6.00Dt was 7.85%. The percentages of with-the-rule, against-the-rule and oblique astigmatism among people with astigmatism were 46.67%, 35.56% and 7.77%, respectively. The average of pupillary distance in male (64.5${\pm}$2.9 mm) was greater than that in female (61.9${\pm}$2.3 mm). Conclusions: Korean opticians were provided some useful information about making up a prescription by this research.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.111-115
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• 2007

Purpose: The aim of this study was to assess vision-related quality of life and modes of refractive error correction. We administered NEI-VFQ (National Eye Institute Visual Function Questionnaire) to 137 subjects in two modes of refractive error correction: spectacles and contact lens wearers. The NEL-VFQ was developed to assess vision-related quality of life with respect to 1) visual symptoms 2) social function as well as difficulty with tasks and symptoms 3) economic issues and health concerns 4) psychological well-being. The NEL-VFQ was translated from English into Korean. Methods: All data were analyzed using SAS 8.0. Student's T-test was conducted to determine significant differences in each of the subscale (${\alpha}=0.05$). Result: The Peripheral Vision subscale score ($mean{\pm}SD$) was $52.2{\pm}32.7$ for the spectacle wearers, $88.6{\pm}18.1$ for contact lens wearers; the spectacle wearers' Peripheral Vision score was significantly lower than contact lens wearers (p=0.0001). There were also significant differences between two groups detected in Color Vision (p=0.001), General Vision (p=0.01) and Health Perception (p=0.01). Conclusion: Contact lens wearers and spectacle wearers were mostly high vision-related quality of life except General Vision and Health Perception. Especially, contact lens wearers were higher vision-related quality of life than spectacle wearers. Further studies on developing of good quality of contact lens will be needed to improve quality of life in ametropia.