• Journal of Korean Ophthalmic Optics Society
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• v.17 no.4
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• pp.403-410
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• 2012

Purpose: The purposes of this study are to investigate accommodative response among emmetropes, spectacle wearer and contact lens wearer, and correlation between refractive error and accommodative respons for each group. Methods: The 72 subjects(144 eyes) who do not have any ocular diseases were participate in this study. Subjects were categorized into emmetropes, spectacle wearer and contact lens wearer by refractive error using closed-field auto-refractometer. We measured dominant eye, naked/habitual visual acuity and refractive error of monocular/binocular vision of refractive error for far/near distance with open-field auto-refractometer and calculated accommodative lag. Results: There were no significant difference of accommodative lag between right and left eye dominant and non-dominant eye, monocular and binocular vision, and spectacle lens wearer and contact lens wearer, However the accommodative lag of binocular vision was severe than monocular vision at near. The lag of myopia was larger than emmetropes, and male was larger than female. Significant correlation was found between refractive error and accommodative lag in total subjects and the same result was found in emmetropes and contact lens wearer. However there were no significant correlation in the spectacle wearer. Conclusions: There were significant difference between emmetrops and myopes in terms of accommodative lag, however accommodative lag of spectacle wearer was not different with contact lens wearer in myopes. There were also significant correlation between refractive error and accommodative lag in emmetropes and contact lens wearer, but the accommodative lag of spectacle wearer was not significantly correlated with refractive error.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.493-498
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• 2014

Purpose: This study utilized the Geographic Information System (GIS) which is one of the representative methods for describing visual distribution, to show the distribution of visions of middle and high school students in 16 cities or provinces in Korea. Method: The data of National Health and Nutrition Examination Survey (NHANES) were analysed from 2009 to 2011 and designed a population-based cross-sectional study. The subjects were total 1,049 students at the age of 13 to 18 and uncorrected vision was provided. Male subjects were 549 (52.3%) and female subjects were 500 (47.7%). Subjects were divided into 16 cities or provinces and average vision of regions were analysed. the differentials of vision among the regions were analysed by as a spatial analysis method. Results: The average uncorrected vision were significant difference by sex (p=0.001). However male and female student groups' average vision indicated no statistically significant difference by region in those 16 cities and provinces. In order to show the differentials of middle and high school students' vision by region with a visual distribution method, the GIS was utilized for mapping. Conclusions: The differentials of vision among regions by GIS provide a visually effective distribution map.

• 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 the Ergonomics Society of Korea
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• v.34 no.1
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• pp.29-43
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• 2015

Objective: The aim of this study is to develop management guidelines and a procedure for an anthropometric suitability assessment of the main control room (MCR) in nuclear power plants (NPPs). Background: The condition of the MCR should be suitable for the work crews in NPPs. The suitability of the MCR depends closely on the anthropometric dimensions and ergonomic factors of the users. In particular, the MCR workspace design in NPPs is important due to the close relationship with operating crews and their work failures. Many documents and criteria have recommended that anthropometry dimensions and their studies are one of the foremost processes of the MCR design in NPPs. If these factors are not properly considered, users can feel burdened about their work and the human errors that might occur. Method: The procedure for the anthropometric suitability assessment consists of 5 phases: 1) selection of the anthropometric suitability evaluation dimensions, 2) establishment of a measurement method according to the evaluation dimensions, 3) establishment of criteria for suitability evaluation dimensions, 4) establishment of rating scale and improvement methods according to the evaluation dimensions, and 5) assessment of the final grade for evaluation dimensions. The management guidelines for an anthropometric suitability assessment were completed using 10 factors: 1) director, 2) subject, 3) evaluation period, 4) measurement method and criteria, 5) selection of equipment, 6) measurement and evaluation, 7) suitability evaluation, 8) data sharing, 9) data storage, and 10) management according to the suitability grade. Results: We propose a set of 17 anthropometric dimensions for the size, cognition/perception action/behavior, and their relationships with human errors regarding the MCR design variables through a case study. The 17 selected dimensions are height, sitting height, eye height from floor, eye height above seat, arm length, functional reach, extended functional reach, radius reach, visual field, peripheral perception, hyperopia/myopia/astigmatism, color blindness, auditory acuity, finger dexterity, hand function, body angle, and manual muscle test. We proposed criteria on these 17 anthropometric dimensions for a suitability evaluation and suggested an improvement method according to the evaluation dimensions. Conclusion: The results of this study can improve the human performance of the crew in an MCR. These management guidelines and a procedure for an anthropometric suitability assessment will be able to prevent human errors due to inadequate anthropometric dimensions. Application: The proposed set of anthropometric dimensions can be integrated into a managerial index for the anthropometric suitability of the operating crews for more careful countermeasures to human errors in NPPs.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.33 no.3
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• pp.45-68
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• 2020

Objectives : This study aims to evaluate the effectiveness and safety of manual and electroacupuncture on glaucoma. Method : We searched 11 electronic databases using index words to identify randomized clinical trials. Meta-analysis of weighted mean difference (WMD) or standardized mean difference (SMD) were used to evaluate the outcomes. Cochrane bias risk assessment tool was used to assess the risk of bias in each clinical study. The collected data was analyzed using RevMan software (ver. 5.3). Results : At the initial stage of data retrieval, 549 papers were searched. After reviewing 37 full texts, a total of 10 RCT studies (426patients, 715 eyes) were selected and 8 RCT studies (357 people, 617 eyes) were involved in meta-analysis. Meta-analysis of 8 RCTs showed that acupuncture alone was more effective in reducing intraocular pressure(IOP) than conventional treatment (WMD = -5.73, 95% CI: [-12.30, 0.83], P = 0.09, I² = 97%) The combination of acupuncture or electroacupuncture with conventional treatment was also effective in lowering IOP (WMD = -1.84, 95% CI: [-2.31, -1.37], P <0.00001, I² = 45%). It was estimated that the combination of acupuncture with conventional treatment was also effective for improving visual field (VF) (WMD = -2.17, 95% CI: [-4.32, -0.02], P = 0.05, I² = 89%) but improvement in visual acuity (VA) was not significant (MD = 0.06, 95% CI: [-0.03, 0.15], P = 0.23, I² = 0%). Subgroup analyzes were performed only for the studies that used open glaucoma as the study's disease and combination of acupuncture or electroacupuncture with conventional therapy would have an effect on lowering intraocular pressure (WMD = -1.68)., 95% CI: [-2.46, -0.90], P <0.0001, I² = 29%). Conclusion : This study suggests that acupuncture treatment for glaucoma may be effective in reducing intraocular pressure and helpful in improving visual field defects. However, due to the small sample size, high risk of bias and high heterogeneity in the methodology, it is expected that further studies will be needed to verify the results. Further studies in large-scale samples based on a minimized biased methodology would be necessary.

• Journal of the HCI Society of Korea
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• v.10 no.2
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• pp.13-19
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• 2015

Display technology has recently made enormous progress. In particular, display companies are competing each other to develop flexible display. Curved display, as a precursor of flexible display, are now used for smart phones and TVs. Curved monitors have been just introduced in the market, and are used for office work or entertainment. The aim of the current study was to investigate whether the curvature of a 42" multi-monitor affects postural control when it is used for entertainment purpose. The current study used two curvature levels (flat and 600mm). Ten college students [mean(SD) age = 20.9 (1.5)] with at least 20/25 visual acuity, and without color blindness and musculoskeletal disorders participated in this study. In a typical VDT environment, each participant played a car racing video game using a steering wheel and pedals for 30 minutes at each curvature level. During the video game, a pressure mat on the seat pan measured the participant's COP (Center of Pressure), and from which four measures (Mean Velocity, Median Power Frequency, Root-Mean-Square Distance, and 95% Confidence Ellipse Area) were derived. A larger AP (Anterior-Posterior) RMS distance was observed in the flat condition, indicating more forward-backward upper body movements. It can be partly due to more variability in visual distance across display, and hence longer ocular accommodation time in the case of the flat display. In addition, a different level of presence or attention between two curvature conditions can lead to such a difference. Any potential effect of such a behavioral change by display curvature on musculoskeletal disorders should be further investigated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1721-1731
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• 2011

This study was performed to determine the levels of depression symptoms among community elderlies and to reveal its related factors, specifically aimed at revealing social and family supports. The interviews were performed, during the period from July 1, to August 31, 2010, to 412 elderlies in urban areas. As a results, significantly higher level of depression symptoms was laid on those with lower social supports and family supports(p=0.000), and the subjects' depression was a negative correlation with social and family support. On multiple regression analysis, the level of depression symptoms was influenced by the variables of social and family support, with or without disability of visual acuity, sense of satisfaction in daily life, number of friends, educational level, with or without spouse, activity of hobbies and urinary incontinence. In conclusion, the level of depression symptoms was so complicatedly influenced by variable factors as well as socio-demographic characteristics, health-related behaviors, health status, social support net-work and social activities. Especially, the level of depression symptoms was more influenced by social supports and family supports.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.3
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• pp.327-331
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• 2011

Purpose: The purpose of this study was an accurate grasp of the astigmatic change due to eyes accommodation on near vision and suggested problems occurring accommodative astigmatism using near glasses. Methods: 154 subjects(308eyes) from 20 to 40 years selected for this study who had many opportunity of near vision. First, far vision corrective refraction measured using the phoropter, and then both eyes opened simultaneously for maintaining the function of binocular put away dot chart 40 cm. One eye was fogging and the other eye measured near vision astigmatism axis and degrees astigmatism using cross cylinder, and then compared with far astigmatism. Results: Increased degree of astigmatism persons on near vision more than decreased or did not changed degree of astigmatism persons, which could affect visual acuity more than 0.75 diopters in 30 eyes with an increase of 9.7% of total subjects. Direct astigmatism and oblique astigmatism were increased on near vision. Astigmatic axes were rotated base in direction on both eyes and 66.9% of subjects were more than ${\pm}$5$^{\circ}$ rotation. Due to the rotation axis of astigmatism, residual astigmatism is expected to occur and expect to adversely affect the eyes. Conclusions: Long-term using the glasses without correction of increased astigmatic and rotated axis on near vision should occur new residual astigmatism and increase the asthenopia also. Considered to be taken astigmatic change on near vision during near refraction examination.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.3
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• pp.65-73
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• 2009

Purpose: This study was conducted to investigate the changes in distance refractive power and reading addition that occur after wearing corrective glasses for prebyopia. Methods: The subjects aged 42 to 75 years who had no ophthalmologic diseases and did not undergo cataract or retina surgery, had a corrected visual acuity of 20/20 and did not have a previous history of wearing corrective glasses for presbyopia. These subjects were divided into 3 groups: the control, reading spectacles and multifocals wearing group and they were measured for distance refractive power and reading addition at their visit. The maximum follow-up period was 73 months. Results: As for distance refractive power, the power tends to shift to hyperopia depending on age (r=0.486, p<.001) and 50.0% of the subjects increased plus power during this study period. Plus power Increments per year in distance refractive power in the reading spectacle wearing group were significantly different with control and multifocals wearing group (p<.05). On the other hand, the multifocals wearing group's increments were not different with control. Increments in reading addition were also increased in the reading spectacles group than in the control and multifocals wearing groups (p<.05). Conclusions: The age related hyperopic shift could be occurred in the elderly people, routine refraction is mandatory. And reading spectacles could induce an age related hyperopic shift and the additional need for reading addition that the prescription of multifocals may reduce changes in distance refractive power and reading addition.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.3
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• pp.59-63
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• 2009

Purpose: To investigate the near horizontal heterophoria of the college students in their twenties on north Kyonggi Province. Methods: The all subjects had not experienced any ocular surgery and have no disease and their mean age is 22.9. As 122 subjects, they are 50 emmetropes and 72 ametropes. The ametropes are all myopia. After distance visual acuity correction with subjective and objective refraction test, evaluated their horizontal heterophoria with red maddox rod. Results: In maddox rod test, the subjects consist of orthophoria 4.9%, esophoria 9.8% and exophoria 85.3%. In the emmetropes orthophoria is 8%, esophoria is also 8% and exophoria is 84%. In the ametropes orthophoria is 2.8%, esophoria is 11.1% and exophoria is 86.1%. The mean size of horizontal heterophoria is esophoria 3.59PD (prism diopter), exophoria 7.04PD and in the emmetropes esophoria is 3.25PD, exophoria is 6.60PD. In the ametropes esophoria is 3.75PD and exophoria is 7.34PD. Conclusions: In the emmetropoes the orthophoria is more than in the ametropes and the esophoria and exophoria is more in the ametropes. But the differences between the heterophoria and emmetropia or ametropia were not significant (p>0.05). The mean size of heterophoria is higher in the ametropes than in the emmetropoes. The distribution range of heterophoria is wider in the male subjects than the female subjects.