• Journal of Korean Ophthalmic Optics Society
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• v.11 no.2
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• pp.131-135
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• 2006

The purposes of this study is examining a wearing tendency of a progressive multifocal lens. We measured refractive error values using subjective and objective refraction method with subjects in 40-65 ages. Also, we investigated and analyzed distribution of addition power and wearing tendency of progressive multifocal lens. Detected addition powers were ranged of +0.75D - +3.00D. In case of average addition, they were detected with +1.18D in 40's, +1.55D - +1.97D in 50's and +2.38D in above 61's age. The distributions of visual ability at a distant were measured that the hyperopia and hyperopic astigmatism 43%, the myopia and myopic astigmatism characteristic astigmatism 7% appeared highly with 36%. The male who uses the interior aspect multi focal lens with the short-range work were appeared the male 20%, the woman 19%.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.4
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• pp.469-476
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• 2012

Purpose: The purpose of this study is to investigate the changes of asphericity according to diameter and direction of the cornea. Methods: The changes of asphericity according to diameter and direction of cornea is measured by using Pentacam(Oculus Co., Germany), as targeting 57 adults (average $27.0{\pm}4.8$, 20 men, 37 women) without any ophthalmic diseases, which may be effective in eyesight, and refractive surgery. Results: As diameter increases in every direction based on the corneal vertex, asphericity has attentively increased (p<0.05), and the size of asphericity in each direction from every measured diameter showed as superior > nasal > inferior > temporal. In group comparison by nearsightness and astigmatism level, asphericity measured high when nearsightness and astigmatism levels were higher, and this appears to be statistically attentive.(p<0.05). Conclusions: Asphericity of cornea significantly increased according to increase of diameter of cornea, and as measured figure or increased quantity appeared differently in all directions based on corneal vertex, so it helps to understand shape of cornea, and considered that is the part to be considered during manufacturing and fitting of RGP lenses.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.05
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• pp.57-60
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• 1993

A finite element-based computer simulation of excimer laser susery was conducted to study some factors on the surgery. In particular, the radius of curvature at the apex of the cornea was examined under various surgical conditions. Corneal tissue was assumed to be a nearly incompressible, linear elastic, homogeneous, isotropic material under very small deformation. The geometry of the human cornea was taken from the experimental data[1]. The simulation utilized ANSYS(Swanson Analysis System Inc.Rev.4.4A). In this study, the major factors which affect the outcomes of the excimer laser surgery were investigated. First, two patterns of surgery with various surgery thickness(40-70micrometers) were examind. The pattern#1 describes the meridian from the apex to the edge of the surgery area to be straight. And the corresponding meridian of the pattern 2 can be expressed as a quardratic function. The results show that the pattern #2 is more realistic and effective. Then, the effects of other factors were investigated based on the pattern #2. Other factors are:various diameters of the surgical area (3-8 milimeters), Young's modules(3.5-4.5MPa), and depth of surgery at the apex(40-70micrometers). Compared with the computer simulation of the radial keratotomy surgery[2], the excimer laser surgery was proven to be more effective in treating myopia patients. In conculusion, the results of the simulation are qualitative agreement with clinical experience[3] indicating the potential of the finite element model of the surgery as a guideline to the surgeon before actual surgery.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.95-100
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• 1995

This study investigated the effects of mechanical factors involved in several corneal refractive surgeries on the surgical outcomes. Then we proposed possible new techniques from the mechanical point of a view utilizing finite element method. The models studied are: circumferential keratetomy, combination of excimer laser photorefractive keratectomy and circumferential keratotomy for myopia treatment, arcuate keratotomy for astigmatism treatment. The cornea was assumed to be nonlinear elastic and almost incompressible material as the most soft tissue in the human body. In the circumferential keratotomy the effect of the incision location was investigated. The angle and location of the incision were varied to predict the surgical outcomes in the arcuate keratotomy. The finite element analysis results showed that the location of incision was a critical factor affecting the surgical outcomes in the circumferential keratotomy. In the combination of the excimer laser photorefractive keratectomy and circumferential keratotomy, it was predicted that the circumferential can increase or decrease the refractive power depending on the incision location or it can be used to adjust the overcorrection of undercorrection. In the arcuate keratotomy for astigmatism, the most diopter changes were predicted when the location and the angle of the incision were 3.0mm from the apex and $90^{\circ}$, respectively. In the arcuate keratotomy, the effects of an incision were studied within the incision area as well as outside the incision area. Also, the arcuate keratotomy with two incisions located on the opposite area of the cornea was also studied. As a conclusion, the finite element method is a useful technique in the area of corneal refractive surgeries to develop new techinques.

• Journal of Genetic Medicine
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• v.8 no.2
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• pp.125-129
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• 2011

Stickler syndrome is a very rare connective tissue disorder. The authors of the present study describe an 11-month-old girl with high myopia, retinal abnormalities, flat nose, cleft palate, retrognathia, micrognathia, short stature and arthrogryposis. Radiological evaluation also showed irregularity of the epiphysis of the femur and tibia and spondyloepiphyseal dysplasia. Genetic analysis using a peripheral blood sample revealed a novel variant c.787G>A (p.Gly246Asp) mutation of the COL2A1 gene. This is the first Korean case with Stickler syndrome confirmed by genetic testing.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.3
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• pp.313-317
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• 2011

Purpose: This study was to assess prevalence of refractive errors and uncorrected refractive errors in elementary school children in Mokpo and uncorrected refractive errors were to be used as the basic data. Methods: Vision tests were conducted on 400 subjects of 1st~6th grades at 3 elementary schools in Mokpo city, and subjective, objective refraction test were also performed to survey uncorrected refractive errors. Results: The prevalence of myopia was 256, 64% of total subjects, Hyperopia was 21, 5.3%, astigmatism was 19, 4.8%. The prevalence of uncorrected refractive errors were increased as higher grade and more oculus dexter higher than oculus sinister. Conclusions: Vision impairment which need an accurate vision correction for elementary school students requires the regular examination and actively correction in order to protect the elementary school students for basic welfare.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.113-120
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• 2021

The objective of this study is to identify the visual function impairment of children with each type of attention deficit hyperactivity disorder(ADHD). The subjects of this study were 49 children diagnosed with ADHD with visual function out of the normal range. The type of ADHD was investigated using the Korean-ADHD Rating Scale and visual function test. The attention deficit type(69.4%) of ADHD was the most common type among children with ADHD with vision problems. Although their overall naked-eye visual acuity was good, about 50% of the subjects showed problems with visual function. For those with the attention deficit type of ADHD, the myopia-related refractive error was high. For those with the hyperactivity type of ADHD, the astigmatism-related refractive error was higher. For those with vergence function disorder, convergence insufficiency was the most common. As there were differences in the visual impairment characteristics of children with different types of ADHD, it is necessary to approach a child's problem behavior through examination and screening for visual function disorders.

• Journal of the Institute of Convergence Signal Processing
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• v.23 no.2
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• pp.70-75
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• 2022

With the spread of various digital devices, devices have become commonplace in modern society. Moreover, due to the increase in device usage and online learning while staying indoors during the COVID-19 pandemic, symptoms such as an increase in myopia in children due to eye fatigue, an increase in young presbyopia, and dry eye syndrome are increasing, and now people are paying attention to eye health. This is different from before. There are various prescriptions for eye health, but in this paper, we would like to propose a training method for enhancing visual function using VR contents. The analog methods of the existing teaching aids for visual function reinforcement training were planned and produced as digital contents, and VR-based training contents were selected from among the various methods carried out with teaching aids at the visual function training center, which can be made into contents. was developed with In the training process for each content, it was proposed to apply eye tracking to the VR device in order to give the user feedback on their participation in the training so that the management and concentration of the training process could be analyzed.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.655-662
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• 2023

Big data research plays a role of supplementing existing social science research methods. If the survey and experimental methods are somewhat inaccurate because they mainly rely on recall memories, big data are more accurate because they are real-time records. Social science research so far, which mainly conducts sample research for reasons such as time and cost, but big data research analyzes almost total data. However, it is not easy to repeat and reproduce social research because the social atmosphere can change and the subjects of research are not the same. While social science research has a strong triangular structure of 'theory-method-data', big data analysis shows a weak theory, which is a serious problem. Because, without the theory as a scientific explanation logic, even if the research results are obtained, they cannot be properly interpreted or fully utilized. Therefore, in order for big data research to become a methodological innovation, I proposed big thinking along with researchers' efforts to create new theories(black boxes).

• Analytical Science and Technology
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• v.37 no.3
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• pp.189-199
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• 2024

In forensic genetics, when it is not possible to confirm an individual's identity through STR profile analysis, additional information about the individual can be obtained using DNA-based phenotypic traits estimation. Recently, various researches have been conducted on methods to determine externally visible characteristics (EVC) such as eyes, hair, and skin color. However, relying solely on such phenotypic traits information has limitations for application in East Asian regions, including Korea. In this study, in order to utilize EVC related to an individual's appearance as investigative information, SNPs related to eye shape, hair thickness, skin color, as well as baldness, body type, high myopia, facial shape, acne, and behavioral habits were explored. A total of 50 SNPs were selected, and a targeted amplicon NGS panel capable of amplifying them all at once was developed. Experimental results confirmed the allelic types and frequencies of the 50 SNPs in 14 samples. We plan to use this panel to investigate the correlation between genotype and phenotype using various samples, and to develop methods for interpreting the results.