• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.441-447
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• 2013

Purpose: The present study was conducted to investigate the axial rotations of toric soft lens during the change of lens wearer's posture, and the relationship between its rotation and corneal astigmatism. Methods: The amount, direction, and speed of toric soft contact lens rotation were measured for 42 eyes (aged 20s) with the rule astigmatism in the straight and lying postures, and it compared between their changes according to corneal astigmatism. Results: There was no significant difference in the axial rotation of lens for the astigmatism prescription between the straight and lying postures. However, the rotation angle was significantly different according to the posture of lens wearer. Rotating directions in straight posture were nasal direction for 20 eyes and temporal direction for 22 eyes. In lying posture, lenses of most wearers were rotated to a direction of lying posture, and the initial rotating speed was very fast in initial wearing for -0.75 D toric lenses, but consistency for -1.25 D toric lenses. The rotation angle in lying posture showed significantly different according to the amount of corneal astigmatism, the lens speed was also significantly different according to the wearing time but not the amount of corneal astigmatism. Conclusions: The axial rotation of toric soft lens was different by the lens wearer's posture and its amount was the greater with the higher degree of corneal astigmatism. Thus, these factors should be considered for the development of toric lens design.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.413-428
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• 2013

Purpose: The purpose of this study was to evaluate students and optometrist opinion of the usefulness of different subjects of optometry curriculum.This date will then be used as base-line data during a process of curriculum development Methods: 292 of ophthalmic optic's students and 123 of optometrists were surveyed in the usefulness of curriculum (five-point scale) followed by statistical analysis of the results. Results: Optometrists gave a higher average score for curriculum usefulness (3.89) than the students (3.71). The subject which showed the highest usefulness for the student was optometry (4.55) but clinical practice was the highest for the optometrist (4.48). There was significant differences (p<.05) on optics, ophthalmology, basic science, optometrist related subject and foreign language but optometry and contact lenses showed high usefulness in common without significant difference. The usefulness of subject for the student showed significant difference according to gender, grade, age, and desired working place and has demonstrated significant difference depend on gender, age, scholarship, total working experience as an optometrist, workplace, and position for optometrists as well. Conclusions: It is necessary to continue research for the development of standard and bench-marked curriculum for ophthalmic optics and also the curriculum, which reflecting the usefulness and needs obtained from ophthalmic optics' students and optometrists need to be developed.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.95-99
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• 2008

Purpose: Even refractive error is perfectly corrected by glasses power, the glasses wearer can feel imbalance and uncomfortable by prism effects. The purpose of this study was to investigate subjective imbalance to vertical yoked prism in visually normal subjects. Methods: Visually normal 37 subjects (aged 20 to 31 y) were fully corrected by soft contact lens and worn vertical yoked prism, base up and base down 1, 2, 4, 6, 8 prism diopter(pd) at random order. A rating scale questionnaire was administered to assess quantitatively subjective imbalance to the yoked prism. The near phoria tests were done using Howell-Kim phoria card at 40 cm distance. Results: For the subjective response of imbalance, base up yoked prism was higher than base down yoked prism (t-test: t=4.67, p=0.00) in over 2 prism diopters. The frequency of subjects who feel imbalance by base up vertical yoked prism is higher for near esophoric group than for exophoric group. Conclusions: To reduce subjective imbalance caused by glasses such as dizzy, it needs to make the minimum prism effect, and base down yoked prism is more effective than base up yoked prism in prism effects.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.3
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• pp.349-354
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• 2015

Purpose: To investigate the changes of corrective values of astigmatism caused by the position of circle of least confusion on retina in refining astigmatic test using cross cylinder. Methods: 62 subjects (115 eyes) aged $22.24{\pm}2.48$ years participated for this study. After astigmatic test using a radial chart, refining test was performed using a cross cylinder in a condition of maximum plus to maximum visual acuity (MPMVA). Astigmatic refining test was repeatedly performed in each condition of which S+0.75 D, S+0.50 D, S+0.25 D, S-0.25 D, S-0.50 D, and S-0.75 D are added to spherical lenses of MPMVA. The measured values were compared with the values in MPMVA condition. Results: As compared with values in condition of MPMVA, change of astigmatic axis was increased with add the power of (+) spherical lenses and (-) spherical lenses. In same spherical condition, change of astigmatic axis was decreased with increment of astigmatic power (p<0.05). The corrective power of astigmatism was reduced with increment of (+) spherical lenses (p<0.05), and was raised with increment of (-) spherical lenses compared with the power in MPMVA condition. In case of adding (+) spherical lenses, difference of astigmatic power increased with increment of corrective astigmatism power in same test condition. Conclusions: In order to obtain a proper values for corrective astigmatism, position of circle of least confusion should be accurately adjusted before the performing an astigmatism's refining test.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.1
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• pp.9-16
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• 2014

Purpose: In this study, we have compared and analyzed customers' and optometrists' notions regarding franchise optical shops and independent optical shops, so that this research proposes a new direction for the optical industry. Methods: A survey was conducted on 152 customer who visited optical shop and 50 optometrist in Ulsan. Results: With regard to franchise optical shop, customers answered as advantages the well-organized system and service, while as disadvantages high prices and lack of communication. The advantages of independent optical shop, on the other hand, were good communication, fair prices, professionalism, while the disdvantages were lack of service, poor interiors, old-fashioned trends. Optometrists answered that advantages of franchise optical shop were service, system, communication, and successive education, while the disadavantages were monotonous interiors, excessive events, and lack of communication. Optometrists also answered that advantages of independent optical shop were service, and communication, while the disadvantages were poor system, lack of events, poor interiors. Conclusions: We could conclude that it is reasonable for optometrists to consider the advantages of their competitors in order to enhance their communication skills and professionalism, which will promote a healthy competition between them.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.125-131
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• 2015

Purpose: The effect of pigmentation in circle contact lens on lens wearers' tear film stability was investigated in this study. Methods: Non-invasive tear film break-up times of 54 normal eyes before and after lens wearing in twenties and the portion of first tear breakup were measured. The frontal and back surface roughness of circle contact lens was further observed with a scanning electron microscope. The clear lens which was made of hilafilcon B and circle contact lenses which were made of hilafilcon B, polymacon and copolymer of HEMA NVP were tested. Results: Non-invasive tear film breakup time was significantly reduced compared with it before lens wearing. In some case, statistically significant difference in tear film breakup time was also observed between circle contact lenses. The tear file break-up was usually early started in lower than upper portion, and in temporal than nasal portion although there was variation in the lens material. The tear film break-up of circle contact lenses made of hilafilcon B was more commonly observed in peripheral portion(pigmented area) compared with clear contact lens made of same material. Conclusions: The present study revealed that the stability of tear film was affected by wearing circle contact lens and the result seems to be used as the basis for the problem solving that can occur due to the pigmentation when wearing circle contact lens.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.499-504
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• 2014

Purpose: This study is to evaluate the accuracy of dry eye screening test by comparing coincidences between three types of questionnaires and objective tests. Methods: 90 adults were classified into the normal and dry eye groups using evaluations of three types of questionnaires (SPEED, OSDI, TERTC-DEQ) and objective tests (NIBUT, Schirmer test). Coincidences-between the results of objective tests and questionnaires were compared and analyzed for dry eye diagnosis. Results: Coincidences between NIBUT test and each questionnaire were 83.3% by SPEED, 77.8% by OSDI and 72.3% by TERTC-DEQ, respectively. Concordance by SPEED was highest among three types of questionnaire. Coincidences between the Schirmer test and each questionnaire were 57.8% by SPEED, 58.9% by OSDI and 73.3% by TERTC-DEQ, respectively, thus coincidence by TERTC was higher than by others. But coincidences by Schirmer test were generally lower than those by NIBUT test. Conclusions: SPEED questionnaire showed the highest concordance with objective test as compared with others. Therefore, SPEED is expected to be used usefully to diagnose dry eyes.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.661-666
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• 2013

The aim of this study was to evaluate the property of heterophoria and fusional reserve in Adults in Jeon-buk Area. We examined the corrected visual acuity, corrected refractive error, heterophoria and fusional reserve of 116 healthy myopes aged from 20 to 44 old who had no strabismus no ocular and phyisical diseases. Using Von Graefe test of horizontal heterophoria Measurement, we measured orthophoria(26.7%), exophoria(52.5%) and esophoria(20.7%) for at near distance. The subjects who had exophoria of 0-6${\Delta}$ in the range of normal state was 38.8%, while the subjects who had exophoria in the range of abnormal state was 61.2%. Reducing fusional reserve was associated with increasing phoria. We found a relationship between asthenopia and fusional reserve of heterophoria and considered that fusional reserve must be examined when we preserve for a patient with heterophoria. Furthermore, Gradient method AC/A ratio was found 4.03 and its relationship to refractive error could not be determined.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.1
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• pp.23-30
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• 2014

Purpose: The present study was aimed to figure out the correlation amongst the evaluation methods for critical micelle concentration, surface tension and protein cleaning efficacy to evaluate cleaning efficacy of contact lens care products. Methods: The critical micelle concentration of surfactants and the actual concentration of surfactants in contact lens care solutions were investigated by employing references published and related information. Surface tension of contact lens care solutions was measured by surface tension device at $25{\pm}1^{\circ}C$, and contact lenses made of lotrafilcon A, comfilcon A and balafilcon A were washed with contact lens care solutions after the incubation in artificial tears for 14 days and their cleaning efficacy was compared. Results: Among the 22 contact lens care products, 9 products provided the label of the concentration of surfactant, and 7 products showed higher concentration of surfactant than the critical micelle concentration reported in references. As a result of measuring surface tension, the surface tension of lens care products for soft contact lens was generally lower than other care products. When examined the removal effect of protein deposited on lens surface, it was known that the care products having lower surface tension showed higher protein removal efficiency. Conclusions: The surface tension is low when surfactant concentration in contact lens care solutions is high, and the removal effect of protein deposited is accordingly increased with the decrease of surface tension. Thus, these indicate the correlation amongst the evaluation methods for cleaning efficacy.

• Korean Journal of Materials Research
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• v.30 no.6
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• pp.273-278
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• 2020

This research is conducted to analyze the compatibility of used monomers and produce the high functional hydrogel ophthalmic polymer containing silane and nanoparticles. VTMS (vinyltrimethoxysilane), TAVS [Triacetoxy(vinyl)silane] and cobalt oxide nanoparticles are used as additives for the basic combination of SilM (silicone monomer), MMA (methyl methacrylate) and MA (methyl acrylate). Also, the materials are copolymerized with EGDMA (ethylene glycol dimethacrylate) as cross-linking agent, AIBN (thermal polymerization initiator) as the initiator. It is judged that the lenses of all combinations are optically excellent and thus have good compatibility. Measurement of the optical and physical characteristics of the manufactured hydrophilic ophthalmic polymer are different in each case. Especially for TAVS, the addition of cobalt oxide nanoparticles increases the oxygen permeability. These materials are considered to create synergy, so they can be used in functional hydrogel ophthalmic lenses.