• Journal of Korean Ophthalmic Optics Society
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• v.18 no.2
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• pp.203-211
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• 2013

Purpose: When we look at the object, we used the dominant eye mainly. For this reason, a prescription of the dominant eye is an important factor for glasses and contact lenses. This study evaluated visual acuity differences between dominant and nondominant eyes through analyzing refractive power changes in both eyes by the ages. Methods: This study was performed to investigate the relationship between refractive error and dominant eye which had the superiority in the function of binocular. 186 subjects without ocular disease were examined on the dominant eye. The dominant eye was examined by the Hole-in-the-card test. For the consistency of the measurements, we tested refractive power in three times by the same person. Results: Using SPSS, the relationship between vision and the dominant eye was analyzed. 135 people of the whole subjects have the dominant eye on right. The Number of the non-dominant eye is 51. We were divided into 3 types, the group under the age of 10 that begins to expose environment factor affect on vision (the average age $8.8{\pm}1.18$) and the age group of 10 to 20 that begins to change refractive power in earnest (the average age $14.1{\pm}2.58$) and the group after the age 20 that began to stabilize vision (the average age $51.8{\pm}17.51$). The visual acuity of dominant eye was higher than non-dominant eye in all age groups. Nevertheless, these results were not statistically significant. Mean astigmatism of dominant eye was smaller than the non-dominant eye, and this is significant, statistically (p=0.017<0.05). Conclusions: It is expected that the balanced eye with a lower level of astigmatism has a more possibility become a dominant eye.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5621-5627
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• 2014

To specify the standard of LASEK surgery, this study examined the determination factors affecting the high order aberrations (HOAs) in preoperative and postoperative LASEK. 51 adult patients (102 eyes) were evaluated at the baseline and 2 months after LASEK surgery from Nov 2011 to Jul 2012. The postoperative HOAs ($0.538{\mu}m$) were higher than the preoperative ($0.341{\mu}m$). In linear regression analysis, the refractive components that affected the postoperative HOAs were $J_0$ of corneal astigmatism (CA, 0.400), $J_0$ of refractive astigmatism (RA, 0.389), corneal astigmatism (CA, 0.282), spherical equivalent (SE, 0.239), refractive astigmatism (RA, 0.213), and pupil size (PS, 0.194) with a high R. In multiple regression, $J_0$ of CA, PS and SE were significant factors with the postoperative HOAs. In conclusion, both HOAs and $J_0$ of CA should be considered when determining the suitable factors for LASEK surgery.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.2
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• pp.147-152
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• 2016

Purpose: This study was designed to be used as the basic visual function data after analyzing and investigating the refractive errors variation between city and rural elementary school children. Methods: To compare with city and rural areas, 2501 elementary school children who lived in Mokpo, Yeongam, Muan, Hampyeong were participated. Objective refraction, Subjective refraction and binocular function examinations were measured. Results: Mean of refractive error of rural areas was -1.47 D in 2012 years, -1.52 D in 2013 years, and -1.40 D in 2014 years. However average of refractive error was -1.65 D in 2012 years, -1.76 D in 2013 years and -1.75 D in 2014 years who lives in city areas. Average myopia was showed higher who lives in rural areas elementary school children than city areas elementary school children. There were significant differences between rural areas and city areas elementary school children (p = 0.03), but there were no significant differences by averagre hyperopia (p = 0.32). Average myopia was showed the tendency of increase as the students get older by analysis compare with rural and city areas elementary school children. It also showed high prevalence of myopia who lives in city areas elementary school children compare with lives in rural areas elementary school children. Conclusions: It is the very important to performed regular visual acuity test and correction during the largest refractive change period and it is necessary to have experts in the visual acuity test.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.1
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• pp.75-81
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• 2012

Purpose: The study tried to figure out accommodative changes by measuring accommodative response, appearing on the full vision correction and low vision correction, with both eyes open-view auto-refractometer (Nvision-K5001, Shin-nippon, Japan). Methods: It carried out objective and subjective refractions, targeting 79 college students (58 males and 21 females) aged between 20 and 30($21.14{\pm}2.00$), by measuring accommodative changes with fixation distance at 1.0 m for eyesight of 1.0 after full version correction. The distances of 5.0 m, 1.0 m, 0.50 m, 0.33 m and 0.25 m for eyesight of 0.8, 0.7 and 0.6 after low vision correction arbitrarily added plus lens were applied. Results: the shorter measure fixation distances were, the greater changes accommodative response showed a tendency in the state of both full vision correction and low vision correction(0.7). The state of full vision correction showed a greater change of accommodative response than that of low vision correction(0.7). Both right and left eyes showed low accommodative responses in the state of low vision correction(0.7) than that of full vision correction. As a result of analyzing accommodative response at an eyesight of 0.8, 0.7, and 0.6 after low vision correction, the poorer eyesight was the lower accommodative response. Conclusions: Low vision correction from a near distance is expected to avoid unnecessary accommodative response, make eyes relaxed and prevent accommodative function disorder.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.347-353
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• 2010

Purpose: An in vitro study was conducted to compare the lipid cleaning efficacy of care solutions on balafilcon A silicone hydrogel (SiHy) lens. Methods: Lipid spoilation was performed by incubating balafilcon A SiHy lenses in phosphate buffered saline (PBS) containing oleic acid, oleic acid methyl ester and cholesterol. Spoiled contact lenses rinsed with PBS were cleaned with surfactant cleaner, alcohol containing cleaner and multipurpose solution (MPS) respectively and repetitive spoilation and cleaning was conducted up to 14 times. To observe the cleaning effect of ultrasonic wave on the lipid deposit, each spoiled lens was ultrasonicated and then compared with non-sonicated lens. Lipids deposit on the contact lenses was extracted by methanol:chloroform (1:1, v/v) solution. High performance liquid chromatography was used to analyze and quantify lipid deposit extracts. Results: The effectiveness of alcohol containing surfactant cleaner on the lipid deposits was better than that of surfactant cleaner and MPS, and the cleaning efficacy was significantly higher in the ultrasonic wave treated group. Lipid deposits were not removed completely by contact lens care solutions so that lipid deposits increased continuously and cumulatively. Conclusions: The cleaning efficacy of contact lens care solutions was not satisfactory to remove lipid deposits on the SiHy lens that new cleaning products specially designed for SiHy lenses are needed to develop.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.399-404
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• 2013

Purpose: This study was to analyse the changes of refractive error and addition in progressive eyeglasses lens wearers. Methods: Data of 244 subjects who have been prescribed progressive eyeglasses lenses were used for analysis. The range of age was between 43~69 old years and they visited the optical shop in Gwangju metropolitan city from 2003 to 2013. According to the refractive state and age, The changes of refractive error and addition was analysed respectively. Results: The changes of distance refractive power by refractive error was showed +0.10 D in emmetropia, +0.07 D in myopia, +0.23 D in hyperopia (p=0.000). The change of addition was showed +0.22 D in emmetropia, +0.29 D in myopia, +0.17 D in hyperopia (p=0.000). The changes of distance power and addition by age was +0.08 D distance refractive power, +0.30 D addition in the group of 40~49 old years, +0.17 D distance refractive power, +0.20 D addition in the group of 50~59 old years and +0.15 D distance refractive power, +0.14 D addition in the group of 60~69 old years (p=0.046, p=0.006). Conclusions: The changes of refractive error and addition of progressive eyeglasses lens wearers in all refractive state and age were gradual increase in the direction (+) diopter.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.373-383
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• 2013

Purpose: In this study, we analyzed refractive power of school children in low income family. Methods: We have done a comparative analysis with 112 subjects of low-income of 17 elementary schools in the Yeongcheon area and low-income children less than -6 D of refractive errors from the Korean National Health and Nutrition Examination Survey Report 2010. Results: Spherical equivalent (SE) with low-income group of nation was -1.99 D for right eye and -1.81 D for left eye, while high income group of nation showed -1.26 D and -1.21 D for right eye and left eye respectively. The SE with low income group in Yeongcheon area was -1.85 D for right eye and -1.81 D for left eye. The SE with orphan was -2.75 D and -2.42 D. Single parent family was -2.10 D and -1.96 D, and two parent family was -1.75 D and -1.73. Conclusions: The lack of attention to children eye care may be one of cause for myopia, so the role of the parents and teacher is very important. However, limited role of parents to children due to low income, it is necessary to provide an institutional strategy and social interest to prevent children vision' in low income family.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.465-471
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• 2013

Purpose: This study was conducted to research effects of influence factors on stereopsis of induced aniseikonia in emmetropia. Methods: 20 college students (a mean age of $22.50{\pm}2.72$ years, 14 males, 6 females) were selected as subjects and all of them had no ocular disease or systemic disease, the refractive correction of spherical equivalent within ${\pm}0.50$ D, the corrected visual acuity of 1.0 or better and the aniseikonia values less than 1% by AWAYA. Subject's dominant eye was checked by Hole in card method and contact lenses of -7.00 ~ +7.00D were fitted to cause anisometropia in dominant eye or non-dominant eye, respectively. And then aniseikonia was induced with spectacles to correct refractive error by contact lenses. Stereopsis was measured by Random Dot Stereo Acuity Test with LEA symbols$^{(R)}$ (Vision Assessment Corporation$^{TM}$, USA). Results: Stereopsis was remarkably reduced by inducing aniseikonia, with induced aniseikonia in dominant eye, with higher diopter of wearing contact lenses to induce anisometropia, with spectacles lenses correction of minus power after fitting contact lenses with plus power and in case of men. Conclusions: It should be considered to correct anisometropia that aniseikonia could cause reduction of stereopsis.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.3
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• pp.285-291
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• 2015

Purpose: The hydrogel lenses have been functionalized with HA(Hyaluronic Acid) using two different methods: construction of an IPN(Interpenetrating Polymer Networks) and formation of CCB(Chemical Covalent Bonding). The lysozyme adsorption and physical properties such as optical transmittance and water content of the hydrogel lenses have been investigated in order to determine whether method is suitable for the application potentials in contact lens industry. Methods: HA have been added to the hydrogel lenses prepared in the Lab using the two different method, e.g. IPN and CCB. The optical transmittance was measured in the wavelength range of 300~800 nm. The water content was measured by the gravimetric method using 0.9% NaCl saline solution. The amounts of adsorbed lysozyme on the contact lenses was analyzed by HPLC after incubation for 12h in artificial tears. Results: The water content of the HA added hydrogel contact lenses was increased, and the lens made by IPN method showed higher water content than the lens made by CCB method. The optical transmittance was over 90% both before and after addition of HA. Comparing the lysozyme adsorption reduction ratio, contact lens manufactured by IPN method was 60.0%, and the lens made by CCB method was 40.4%. Conclusions: CCB method is appropriate to distribute the functional material evenly throughout the lens, whereas IPN method is effective for the case of giving the functionality on the lens surface without phase separation.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.3
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• pp.355-362
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• 2015

Purpose: To investigate the effects of the transmittance of diffusive blurson visual acuity and contrast sensitivity. Methods: Visual acuity and contrast sensitivity were measured by using Optec$^{(R)}$ 6500 in Healthy 30 subjects aged $22.83{\pm}0.50$ (male 13, female 17) who were recruited from university students. Cataract simulator was used as a tool for diffusive blur. Visual acuity and contrast sensitivity were measured with varying the transmittance of diffusive blur in order to simulate progression of cataract and concentration in fog. Results: Visual acuity was reduced proportionally with decreasing the transmittance of the diffusive blur as follows: $VA(T)=1.84{\times}10^{-2}T-0.645$. Contrast sensitivity was decreased in all spatial frequencies. Contrast sensitivity in a high spatial frequency band was a greater effect and was off the normal range of contrast sensitivity. The peak of contrast sensitivity was moved in the direction to low frequency. From an intersection point of contrast sensitivity function, we could calculated the transmittance of the diffusive blur being off the normal range and the shift to peak spatial frequency. The peak of contrast sensitivity function was observed to move from 6 to 3 cpd at transmittance of about 78.70%, the contrast sensitivities for all frequencies at transmittance of about 69.71% were deviated from the normal range. Conclusions: The transmittance of diffusive blur causes a reduction in visual acuity and contrast sensitivity, a deviation of normal range of contrast sensitivity, and a shift of peak contrast sensitivity. Therefore the more attention is required when suffering from cataracts or driving in fog.