• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.357-363
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• 2013

Purpose: To investigate the visual function with prescription swimming goggles. Methods: 15 university students (mean age: $22{\pm}1.54$ years) participated, with a mean distance refractive error of RE: S-1.67 D/C-0.40 D, LE: S-1.70D/C-0.37 D. Inclusion criteria were no ocular pathology, able to wear soft contact lenses to correct their refractive error to emmetropia and able to swim. Participants were fitted with contact lenses to correct all ametropia. Subjective evaluation for satisfaction of visual acuity, asthenopia and balance were also measured using a questionnaire while wearing swimming goggles with cylinder (C+1.50 D, Ax $90^{\circ}$) compared with plano sphere outside the swimming pool area. Visual acuity was assessed using the same ETDRS chart. The prescription swimming goggles powers were assessed in random order and ranged in power from S+3.00 D to S-3.00 D in 0.50 D steps. Results: Subjective evaluation was significantly worse for the swimming goggles with cylinder than for the plano powered goggles for all 3 questions, visual acuity, asthenopia and balance. Visual acuity were significantly affected by the different power of the swimming goggles (p<0.05), but there was no significant difference between the in-air in-clinic and underwater in-swimming pool measures (p=0.173). However, visual acuity measured in the clinic was significantly better than underwater for some swimming goggle powers (+3.00, +1.00, +0.50, 0, -1.00 and -2.00 D). Conclusions: Wearing swimming goggles underwater may degrade the visual acuity compared to within air but as the difference is less than 1 line of Snellen acuity, and it is unlikely to result in significant real-life effects. Having an incorrect cylinder correction was found to be detrimental resulting in lower score of satisfaction. Considering slippery floor of swimming pool area, it can be a potential risk factor. Therefore, it is important to correct any refractive error in addition to astigmatism for swimming goggle.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.3
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• pp.275-280
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• 2010

Propose: Due to the rapid growth of medical technologies and the increasing population of older people, we investigated clinical status of ocular dimensions and visual acuity for pre and post cataract surgeries of people over age 90. Methods: From March 2007 to February 2009, we investigated eighty-two eyes of forty-eight patients who had undergone cataract surgeries at an ophthalmic clinic (Ansung, Kyungi-do), investigated maximum corrected vision, axial length, anterior chamber depth and accompanied ocular diseases before and after the surgeries based on the collected data. Results: As patients aged, axial length unchanged but anterior chamber depth decreased over all due to the increase of intraocular lens thickness, and men tended to have a higher degree than women. Seventy-one (86.6%) of eighty-two eyes showed improved corrected vision than before surgeries and forty-three (52.4%) eyes could see more than visual acuity of 0.5. Conclusions: Patients with the systemic disease and accompanied ocular disease showed low vision less than 0.5 after cataract surgery compared to same healthy age peoples. But the others improved correction visual acuity more than 0.5, so the cataract surgery was surely necessary for people over 90 years old and also the presence of ocular disease could have a great influence on correction visual acuity.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.2
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• pp.95-106
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• 2007

The purpose of this study was to investigate effect of spectacle correction therapy instead of occlusion therapy for refractive amblyopia treatment. Spectacle correction were prescribed to give the same effect as a occlusion therapy by under correction for normal eye and there was no additional treatment but only spectacle correction for hyperopic amblyopia. The results can be summarized as follows: 1. In hyperopic amblyopia after correction, initial visual acuity($Mean{\pm}SD$) was $0.36{\pm}0.13$ and final visual acuity($Mean{\pm}SD$) was $0.82{\pm}0.23$. 2. Regardless with age, there was significant differences between initial acuity and final acuity, it shows improvement in visual acuity after spectacle correction treatment. 3. Initial correction age did not influence the length of treatment and success rate of treatment, so that ambyopia correction effect not related with age. 4. Compared with initial visual acuity with final visual acuity, initial visual acuity was in proportion to final visual acuity. 5. Incidence was higher in hyperopia and hyperopic astigmatism than myopia and myopic astigmatism in refractive amblyopia group and the therapy was more effective for hyperopia and hyperopic astigmatism than myopia and myopic astigmatism. 6. Treatment was effective even for children who is older than 8 years.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.4
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• pp.337-344
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• 2006

Purpose: To evaluate the vision-specific Quality of Life according to modes of refractive error correction in myopia. Method: This study included subjects from two different universities in Korea during March 2005 to June 2005. The following subjects (470) were university students, university faculty members, and their immediate families; all of whom were over the age of 19 and all who had refractive error of some sort. The four focus groups consisted of 171 spectacle wearers, 154 contact lens wearers, 123 refractive surgery patients, and 22 post-refractive surgery patients who returned to wearing glasses. The study of Vision-Specific Quality of Life used QIRC - The Quality of Life Impact of refractive Correction Questionnaire, which was translated by our group from English into Korean. Using analysis of co-variance (ANCOVA) and adjusting for age, sex, job, economic status, and education level, we examined and compared the QOL mean scores of the three groups (glass & contact lenses wears, refractive surgery patients, and post-refractive surgery patients who returned to wearing glasses). Results: After adjusting for major compounding variance, the research results showed the highest QOL mean score of 43.2 for the group who had received refractive surgery, 37.1 for the glasses & contact lenses group, and 33.4 for patients who had returned to wearing glasses after refractive surgery. There were significant differences between the three groups (p=0.001). Conclusion: Refractive surgery has shown a significant contribution to improve the QOL in myopia patients. However, upon our investigation, patients who underwent refractive surgery and returned to wearing glasses had a lower QOL compared to non-refractive surgery patients who wore glasses/contact lenses. Upon concluding our studies that shows that refractive surgery does not always conclusively bring higher QOL, we would like patients to carefully consider their options before undergoing refractive surgery in the future.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.2
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• pp.79-85
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• 2000

This study was investigated the refractive state and the analysis of ametropic frequency among schoolchildren who were the three grade in W elementary school in Suwon. Total 488eye (244 persons) were examined by the trial-lens set and the questionary. Through Trial-Lens set verification, several factors related to ametropic frequency were obtained as the following. Among the 244 persons, the students who wear spectacles or need to wear spectacles were 27.3%, among the 27.3% students, the students who have low visual acuity below 0.3 were 6.3%. The ametropia eyes among the total eyes were 27.3%. Among ametropic eyes, myopia and hyperopia were 25.4% and 1.9%. Among the total ametropic errors were low refractive error were 71.4%, and middle refractive error were 28.6%. In ratio myopic frequency, it was statistically related to the refractive errors with the environments factors such as reading distance & habits, T.V watching distance. Among the students belonged to below 0.7 visual acuity, the wear spectacles students were 63.3%. The ratio of anisometropia was 3.4%.

• 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 Korean Ophthalmic Optics Society
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• v.16 no.3
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• pp.319-325
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• 2011

Purpose: The relativity of factors between low vision and socioeconomic status were investigated. This study represented the preliminary data for establishment of public eye health policy. Further, this report would encourage people to change the social attitudes about the eye health equity of the nation. Methods: The number of people (2,514 people) who have been tested the forced visual activity were examined as it was referred the Korea National Health and Nutrition Examination Survey (KNHNE) of 2009-year data. The prevalence rate of low vision of subjects which are related with house income, education level and occupations were conducted with ttest and chi square test. Besides, the Binominal Logistic Regression was conducted to measure the odds ratio of the subjects. Results: In outline, the prevalence rate of low vision was high with low house income, low education level and low function. The odds ratio represented that 2.77(95% CI, 1.72-4.47) at low house income group and 4.02(95% CI, 1.75-9.23) at the case of below primary school education level. Moreover, the results of unemployed group showed 3.65(1.14-11.68) from the odds ratio measurement. Conclusions: The eye health policy need be instituted which is broad and meticulous support to ease the eye health equity of low eye sight patients. For instance, the education about eye health, examination business of eye disease, and education of assistant units which are useful for low eye sight would suggest practical solution.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.6
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• pp.155-163
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• 2012

At present the letter sizes of traffic sign are variously designated as 22 cm through 60 cm, however the basis for determination has not been found so far. Driver's visual acuity for getting a driver licence is required higher than 0.5. In order to interpret the information of traffic signs effectively, the minimum requirement of driver's visual acuity must be applied to determine the letter size of traffic sign. Therefore we reviewed that a driver with visual acuity of 0.5 could read the current letter sizes of traffic sign. In addition, a methodology was developed to determine the letter size of traffic sign satisfied with the driver's visual acuity of 0.5. This study established scenarios that were composed of visual acuity, reaction time, the number of lane and the letter sizes of traffic sign for each scenario were proposed. Current letter size of traffic sign would not be difficult for drivers with minimum visual acuity of 0.5 to recognize the contents or information of traffic signs. The method developed in this research has an advantage that can consider a human factor like driver's visual acuity for the design of traffic signs. There is also a meaning of making a basis for the letter size of traffic sign.

• Journal of Korea Entertainment Industry Association
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• v.15 no.1
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• pp.191-197
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• 2021

This study studied the effect of visual difference on balance and walking ability in college students' life care. The study was conducted on 45 students attending H University in G City, divided into control groups (n=22, not wearing glasses and contact lenses) and experimental groups (n=23, wearing glasses and contact lenses). In not wearing glasses and contact lenses, the subjects measured visual acuity with logMAR charts, evaluated their balance ability with BIOrescue, and evaluated walking ability with G-Walk. The results of this study showed that the experimental group had statistically significantly lower vision than the control group in the visual acuity measurement(p<.01). Static balance ability was statistically significant increase in center of mass movement of the right foot in the experimental group compared to the control group(p<.05). Dynamic balance ability was statistically significantly reduce in limit of stability for groups of experiments compared to control group(p<.05). The walking ability was statistically significantly shorter on step length and stride length, swing of the experimental group compared to the control group in the right foot(p<.05). The findings showed that the visual difference in university students reduces balance and walking ability. Therefore, university students with poor visual acuity are recommended to correct of visual acuity to prevent collision and falls in their daily lives.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.1
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• pp.1-10
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• 2016

Purpose: The study was aimed to suggest the most effective color of the tinted lenses by evaluating the effect of the prescription with tinted lenses on the visual quality of the elderly at the age of the sixty or more. Methods: The visual acuity of fifty subjects at the age of sixty or more (17 males, 33 females with the averaged age of $71.0{\pm}6.3$) were corrected to have the visual acuity at a far distance of 0.5 or more using a trial lens frame, and non-tinted, brown-tinted, and gray-tinted lenses were randomly applied on the trial frame. The minimum legibility and minimum separability were measured at a far distance in the aspect of the visual acuity and calculated as LogMAR and then, the visual acuity was compared. The stereopsis and contrast sensitivity were also estimated at a near distance in the aspect of the visual function. The participants' preference for tinted lenses and their subjective symptoms of the visual perception and the movement were further surveyed. Results: The best minimum legibility and minimum separability was shown when wearing non-tinted lenses, and brown-tinted and gray-tinted lenses were in the next. The stereopsis and the contrast sensitivity at a near distance and the visual perception was the best when wearing brown-tinted lenses. It was surveyed that the subjective discomfort was the biggest when wearing gray-tinted lenses, and brown-tinted lenses were the best in the aspect of the subjective preference. Conclusions: As the result of this study, it was revealed that the visual acuity and visual function could be improved by the use of tinted ophthalmic lenses however, its change of visual acuity and visual function was not completely correlated with the subjective satisfaction. Therefore, the appropriate color of ophthalmic lenses should be selected in accordance with the individual visual perception and the main vision lifestyle in the elderly generation. From the present study, the use of non- or brown-tinted lens and brown- or gray-tinted lens can be recommended for distance work and near work, respectively, in the elderly generation under the illumination of about 1,000 lux.