• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.91-94
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• 2007

This research was investigated to find out the examinees' refractive problems within heterophoria using Torrington method. The number of subjects ware approximately 327 and subjects were sourced from the 12th grade student at high school in Kwang-Ju city. Result obtained shows 21.4% of emmetropia and 78.6% of ametropia. Most of refractive errors were myopia and due to it's condition, frequency of ametropia and emmetropia at the similar rate. However, one that consist of refractive problems, it's myopia contains 74.9% of heterophoria. Due to emmetropia, horizontal heterophoria have 45.7% of exophoria and 4.3% of esophoria. Myopia shows 11.4% of esophoria and 63.5% of exophoria. Hozizonda heterophoria shows 5.7% of emmetropia and myopia of 22.4%, than average of esophoria shows $4.3P{\Delta}$ and case of myopia, it was $3.4P{\Delta}$. Case of Exphoria, emmetropia have $8.8P{\Delta}$ and within myopia $8.0P{\Delta}$. Vertical heterophoria owns $2.2P{\Delta}$ within emmetropia and case of myopia $4.3P{\Delta}$ was shown. Which shows myopia result value higher than emmetropia.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.93-96
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• 2007

Research was taken its place in Dong wun elementary school in Gwang ju city. Subject ages were somewhere around 9 to 13. Among total number of 1,196, subjects with emmetropia were 384 people (32.1%), with 22.56% of 9 year old students, 16.01% of 10 year old student, 36.45% of 12 year old student, 39.11% of 13 year old. When age increases, the rate of emmetropia increase as well. Gender dependence of emmetropia rato was 31.07% for boys and 33.33% for girls, which proves girls with higher emmetropia ratio than boys. Among subjects with binocular vision acuity lower than 0.7, those require spectacles, only 37.5% of 9 years old students, 30.3% of 10 year old students, 44.64% of 12 year old students, and 30% of 9 year old students were wearing glasses. It shows that spectacle-wearing ratio is very low in spite of visual acuty lower than 0.7.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.77-80
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• 2001

To research the ametropia in the west seoul, 510 eyes were tested by the object and subject methods. The results were as follows. 1. Among the 510 eyes, myopia is 71.9%, hypropia is 22.1%, and emmetropia is 5.8%, respectively. 2. In test over the 20 ages, myopia is 66.9%, hypropia is 7.1%, and emmetropia is 23%, respectively. 3. In test under the 20 ages, myopia is 76.6%, hypropia is 3.8%, and emmetropia is 19.6%, respectively.

• Current Optics and Photonics
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• v.3 no.6
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• pp.597-604
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• 2019

This study was performed to evaluate objective visual quality and ocular scattering in myopic refractive-surgery patients, compared to emmetropes. Optical vision-quality parameters (modulation transfer function (MTF) cutoff and Strehl ratio) and objective scattering index (OSI) were measured using an optical quality analysis system (OQAS II) based on the double-pass technique. In all subjects, the higher the MTF cutoff and Strehl ratio, the lower the OSI and ocular higher-order aberrations (HOAs). The MTF cutoff and Strehl ratio for the laser-assisted subepithelial keratectomy (LASEK) group were lower than those for the emmetropia group, while the OSI, ocular HOAs, and spherical aberration (SA) for the LASEK group were higher than those for emmetropia group. Ocular scattering would be one of the important factors in regard to visual quality. Therefore, the quality of the retinal image in the LASEK patients has been shown to reduce the quality of vision more than in the emmetropes.

• 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 Digital Convergence
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• v.14 no.10
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• pp.375-380
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• 2016

This study aimed to evaluate the possibility for assessment of binocular visual function about alteration for near point of convergence (NPC). Study subjects were total 30 (emmetropia 16, myopia 14), who had no eye disease except for the phoria and monocular corrected vision 1.0 and over. Near point of accommodation (NPA), NPC and phoria test were measured both at ordinary and stimulation of +1D. Ordinary NPC was 1.77cm shorter than NPC stimulated +1D and the NPC of emmetropia was shorter than that of myopia. The difference between NPC stimulated +1D and ordinary were increased in the emmetropia. As the NPC increased, the AC/A ratio was elevated and the feature of near exophoria appeared. The results suggested that the alteration of NPC might substitute AC/A ratio for reference variable of binocular vision. If converged and analyzed comparatively with another binocular visual evaluation test, the alteration of NPC could be developed for substitution of evaluation test.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.61-65
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• 2002

This study examines how the average presbyopic additions and eye refraction state of old ages in city may be different to that island. There were 677 of the old who were 50 or over 90 in the sample. The visual acuity test was done by objective and subjective methods and used for near-chart program. The far-point refraction state and power of the additions lens results were as follows ; 1. Of far-point refraction state in city peoples; male: emmetropia 10%, myopia 17%, hyperopia 19%, mixed astigmatism 38%, etc. 16% female : emmetropia 20%, myopia 20%, hyperopia 20%, mixed astigmatism 27%, etc. 13% 2. Of far-point refraction state in island villages ; male : emmetropia 13%, myopia 17%, hyperopia 22%, mixed astigmatism 40%, etc. 8% female : emmetropia 7%, myopia 13%, hyperopia 26%, mixed astigmatism 44%, etc. 10% 3. Average presbyopic additions states has been presented no discrimination ; male: 50 to 60 : +1.25 or +1.50D, 61 to 65 : +1.75 or + 2.00D, 66 to 70 : +2.25 or +2.50D 71 to 75 : +2.75 or +3.00D, 76 to 80 : +3.25 or +3.50D, over81 : +3.75D female : 50 to 60 : +1.25 or + 1.50D, 61 to 65 : +1.75 or + 2.00D, 66 to 70 : +2.25 or +2.50D 71 to 75 : +2.25 or + 2.50D, 76 to 80 : +2.75 or +3.00D, over81 : +2.75 or +3.00D 4. Under the condition of wearing lens, the average working time was 1 or 2 hour but some people used over 5 hours. 5. Generally, it has been investigated the old ages peoples has ocular diseases and cataract was the most common.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.201-206
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• 2006

The purpose of this study is observed effect of cycloplegia in emmetropia with use of cycloplegia. We examined the naked visual acuity, mainfest refraction, 105eyes with emmetropia(under SE ${\pm}0.50D$, Cyl ${\pm}1.00D$) after the use of cycloplegia. We used Nidek ARK-700 autorefractometer. Sexual difference of mainfest refraction error showed in male -0.67D, female -0.92D and difference of the CR and the MR male 0.5D, female 0.81D the total mean 0.69D. The naked visual acuity were in male 0.82, female 0.74, total mean 0.77. Age comparison, difference CR and MR were total mean 0.69D and 13 years group 1.1D were the highest. The naked visual acuity were in the highest 10 years group 0.86. Effect of cycloplegia was $0.69D{\pm}0.79$ in emmetropia and visual acuity was $0.77{\pm}0.21$. The optician, it will not be able to use cycloplegia, must pay attention spectacle prescription unnecessary and over correction in condition below -0.75D MR, above 0.77 visual acuity.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.1
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• pp.71-82
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• 2005

The aim of this study was to provide fundamental data for the factors influencing the asthenopia of emmetropia with phoria and alleviation of asthenopia. A total of 348 subjects, aged between 19 and 30 years old, who had no strabismus, an eye trouble or whole body disease, were examined using corrected visual acuity, corrected diopter, stereopsis and suppression tests from September of 2002 to September of 2004. We excluded 21 subjects for the following reasons: if they had an amblyopia affecting binocular vision or inaccurate data. After these exclusions, 327 subjects remained. We then individually measured the refractive error correction, pupillary distance, optical center distance, phoria, convergence, accommodation and the AC/A as well as the asthenopia during binocular vision using a questionnaire. After analysis of factors affecting asthenopia, we also examined the reductive effect of a prism on the asthenopia in subjects who had asthenopia. To determine the factors affecting asthenopia during binocular vision, statistic analyses were carried out using the Chi-square test and the multivariate Logistic regression model. The results of this study were as follow. For asthenopia during near binocular vision of emmetropia with phoria, in case of the lower the accommodation and convergence, a significantly higher rate of asthenopia was observed (p<0.001). When the AC/A is lower, the higher the rate of asthenopia was observed but not significantly and there was no association between phoria and asthenopia. When the multivariate logistic regression model was used to determine factors affecting binocular vision of emmetropia with phoria, in case of the lower accommodation and convergence, a significantly higher rate of asthenopia was observed. when the phoria is esophoria or higher exophoria, or when the AC/A is lower than normal, the higher the rate of asthenopia was observed but not significantly and there was no association between phoria. AC/A and asthenopia. Therefore accommodation and convergence could be predictive factors for asthenopia during near distance binocular vision. Prism was used among' subjects who had asthenopia during near distance binocular vision, the symptom of asthenopia was eased up to 74.2% in emmetropia with phoria.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.2
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• pp.175-183
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• 2010

Purpose: This study investigated the impact of ametropia and myopia on health-related quality of life (QoL) measures in elementary schoolers. Methods: Elementary school children of 92 aged 12 to 13 were divided into emmetropia and myopia groups by spherical equivalent. Then myopia was classified into the low, moderate and high myopia groups. Vision-related QoL scores were determined using PedsQL 4.0 (Pediatric Quality of Life Inventory) with physical health (8 items), emotional functioning (4 items), social functioning (5 items) and school functioning (5 items). Results: The total QoL score in the myopia group appeared lower than that in the emmetropia group, however the difference was not statistically significant (p>0.05). When it comes to physical health (running or exercising) and social functioning (getting along with friends or being teased)-related questions, the QoL score in myopia was low compared with the emmetropia group (p<0.05). High myopia showed a low score in physical health items but there was no significant difference in overall QoL scores in comparison with other groups (p<0.05). Conclusions: Refractive errors does not have a great impact on the total health-related QoL in elementary school children but it causes discomfort in physical health and social functioning.