• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.125-130
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• 2007

The aim of this work was to study the relationship between subjective symptoms and binocular function during near work in forty one(12-17yr) schoolchildren. CISS symptom survey, amplitude of accommodation, accommodative facility, neagative relative accommodation(NRA)/positive relative accommodation(PRA) near point of convergence(NPC), heterophoria, AC/A ratios were measured. The results of measurement were compared with normal expected value of each test and classified into normal and abnormal group. Accommodative insufficiency was more general than convergence insufficiency and esophoria was greater than exophoria. NRA/PRA showed very high and AC/A ratios were very low compare with normal expected value. The results of CISS was as follows; most frequent symptom was tired, mean score was $16.63{\pm}7.49$, mean number of symptoms were $10.07{\pm}3.04$, and mean number of serious symptoms were $1.98{\pm}2.13$. After classified into 4 groups according to score of symptoms, number of symptoms, and degree of symptoms and then analyze the correlation compare with binocular vision test results. NRA was most correlated with group comparison, accommodative facility was most correlated with score of symptoms, NRA was most correlated with number of symptoms, and near horizontal phorias were most correlated with serious symptoms. NRA showed most correlative relation with near symptoms.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.9-15
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• 2009

Purpose: The aim of this study is to examine various national standards and to suggest problems and improvements on KS (Korean Industrial Standards) in spectacle frames. Methods: We surveyed the latest published KS, ISO (International Organization for Standardization), JIS (Japanese Industrial Standards), DIN (Deutsches Institut fur Normung) and ANSI (American National Standards Institute) standards with relating spectacle frames. The titles that were considered in comparative study were terms and vocabulary, measuring system and terminology, marking, requirements and test methods, formers, screw threads, and others. Results: There were 9 different languages such as English (USA and UK), French, Russian, Japanese, Chinese, German, Italian and Spanish for the lists of equivalent terms and vocabulary in all standards except KS and ANSI, but gave an explanation for terms and vocabulary in only KS. Complementary terms and definitions were not existed in annex of KS and ANSI for measuring system and terminology, but they were included in annex of standards of the others. KS and ANSI standard for requirements and test methods differed from the ISO revision. Except JIS and ANSI, standards of formers were almost identical. KS standard of screw threads were similar to JIS. Standards of welded joints and nickel release did not exist in KS. Conclusions: All standards except ANSI tend to follow ISO, especially DIN is almost entirely identical to ISO. But KS is behind the times because it has been amended lately or established in accordance with older editions of ISO. Therefore, in order to assist quality control and safety for spectacle frames, KS standards shall be superseded by the specifications which is identical to ISO within a reasonable time.

• 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.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.107-116
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• 2000

This study is of investigation of refraction error, spectacles and contact lenses wearing state, visual acuity test, ophthalmologic common sense and vision care, using questionnaire study for 850 male and female high school students in Kunsan and Chongup City, Cheolla North Province. The results are as follows: 1. Among the 823 answerers, emmetropia is 18%, myopia is 55.1%, and hyperopia is 7%, respectively. 2. Among the 837 answerers, 381 students(45.5%) wear spectacles or contact lenses. Among the 381 students who wear spectacles or contact lenses, 78% wear only spectacles, 4% wear only contact lenses and 18% wears spectacles sometimes or contact lenses sometimes. 3. The places where the answerers had visual acuity test to wear spectacles or contact lenses are optical shop(64.7%), hospital(28.3%), unchecked(4.2%) and the others(2.7%). The places where the answerers had visual acuity test to change their spectacles or contact lenses are optical shop(82%), hospital(28.3%), unchecked(6.6%) and the others(1.9%). 4. As for the period of visual acuity test, from 6 months to one year is 54.1%, within 6 months is 9.2%, from one year to two years is 29.5%, and more than two years is 7.2%. 5. The contact lens wearers purchased their contact lenses at optical shops(94%) and at hospital(6%). 6. The reasons why they like wearing contact lenses are their appearance(51.2%), convenience in physical excercise(23.l%), lighter weight than spectacles(9.8%) and the others(15.7%). 7. As for the spectacles frame they like, plastic frame is 24.4%, gold or silver plated frame is 43.4%, coloured frame is 32.1%. 8. As for the considerations in choosing spectacles frame, their design is 37%, their quality is 36%, their price is 14.7% and their brand is 12.5%. 9. As for the period for changing spectacles, 10.5% is within 6 months, 57.3% is 6months to 1 year, 22.4% is 1 year to 2 months and 9.6% is more than 2 years. 10. There is a false fact, in Korea, that even though one has his poor eyesight, not wearing custom is helpful for the eyesight recovery. As for their conviction of the false fact, 10.5% of the answerers have 100% conviction, 22.5% of them have 22.5% conviction, 49.5% of them have 50% conviction and 17.5% of them don't have any conviction. 11. 48.5% of the answerers are interested in their vision care while 51.5% of them are not interested at all. As for the way of vision care, the vision-care way to keep enough distant when they are watching TV, when they are using computers and when they are reading, is 49% while the vision-care way such as hypogastric breathing or eye massage is 11%. And alimentotherapy is 4% and the rest who are not interested in vision care is 36%. 12. When they come to an age, the students who want vision correction operation are 45.9% while the students who do not want it are 27%. The students who do not have any idea about the operation are 27.1%

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.2
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• pp.209-213
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• 2012

Purpose: To assess the repeatability of the monocular spherical endpoints, a test was performed with four methods which are the retinoscopy, the MPMVA (maximum plus maximum visual acuity) method, the R/G duochrome method, and the crossed cylinder method. Methods: The monocular spherical endpoints was measured by four kinds of method (Retinoscopy, MPMVA method, R/G duochrome method, Crossed cylinder method) on 20 subjects (40 eyes) of average age 23.0 year-old men and women. After a week, retest was performed by same procedure and the test-retest repeatability was assessed by using the Bland-Altman plot analysis. Results: The test-retest mean difference of retinoscopy was the smallest diopters of -0.03 and that of R/G duochrome method was the largest diopters of -0.19. The upper/lower 95% limits of agreement for repeatability was the narrowest in retinoscopy and was the widest in crossed cylinder method. When compared the spherical endpoints of each eye between by retinoscopy and by other three methods, the error rate of ${\pm}0.25D$ in total eyes was 85% in MPMVA method, 80% in R/G duochrome method, and 24% in crossed cylinder method. Conclusions: Test-retest repeatability is the highest in the retinoscopy, and the retinoscopy, the MPMVA method, and R/G duochrome method are suitable for monocular spherical endpoints test.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.15-20
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• 2008

Purpose: To study on the confidence of dry eye diagnosis methods which need to prescribe contact lens. Methods: Non-invasive tear film break-up time (NIBUT) and tear film break-up time (TBUT) were measured in forty healthy subjects in their 20s, and then the subjects were classified into normal eye and dry eye. The results of McMonnies questionnaire, tear prism height measurement, Hardtack test, blink rate measurement and Schirmer test were compared with the results of NIBUT and TBUT. Results: The results of NIBUT and TBUT were as follows; 20 subjects had normal eyes, 10 subjects had dry eyes in both NIBUT and TBUT, and 10 subjects showed different results. In McMonnies questionnaire, the score of normal eye group averaged 8.2 and that of dry eye group averaged 18.5, which showed statistically significant difference. Furthermore, 100% of normal eye group classified by the results of NIBUT and TBUT corresponded with the result of McMonnies questionnaire and 90% of dry eye group showed the correspondence. Tear prism height of normal eye group averaged 0.32 mm and that of dry eye group averaged 0.23 mm, which were significantly different. Hardtack test, blink rate measurement and Schirmer test without local anesthesia showed no statistically significant difference between normal eye group and dry eye group. Conclusions: On dry eye diagnosis methods, the results of McMonnies questionnaire and tear prism height measurement had close correlation with the results of NIBUT and TBUT.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.3
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• pp.227-233
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• 2016

Purpose: On this study, we compared the relationship of dynamic stereoacuity according to the dominant eye, degree of dominant eye, and dominant agreement eye and hand. Methods: For 130 adults (male 70, female 60), mean age of $21.06{\pm}2.21years$ old, dominant eye, degree of dominant eye were measured by objective examination by using the diameter $3.8cm{\times}3.8cm$ thin ring, the dynamic stereoacuity were measured by three-rods test (iNT, Korea). Results: Dynamic stereoacuity according to the dominant eye was center dominant eye without dominance was $14.97{\pm}13.80sec$ of arc, right eye $22.10{\pm}20.01sec$ of arc, left eye $22.31{\pm}20.39sec$ of arc. Dynamic stereoacuity was better when there was no dominance, but the correlation of the dominant eye with dynamic stereoacuity was very low. When Dynamic stereoacuity was separated by in the Center, Mild, Strong, dynamic stereoacuity was $14.97{\pm}13.80sec$ of arc, $20.76{\pm}15.73sec$ of arc and $24.45{\pm}25.60sec$ of arc respectively. The dynamic stereoacuity results were worse when dominance was stonger. However dynamic stereoacuity was better than Center when the degree of dominant eye was rather strong in the dominant left eye. Dynamic stereoacuity according to the dominant eye and hand showed that right eye and hand was $22.63{\pm}20.54sec$ of arc, left eye and hand was $17.36{\pm}10.13sec$ of arc, right eye and left hand was $14.79{\pm}7.05sec$ of arc, left eye and right hand was $22.97{\pm}21.42sec$ of arc so dynamic stereoacuity was comparatively good when the dominant hand was left. Conculsions: Correlation between the dynamic stereoacuity according to the dominant eye, degree of dominant eye was low, however when degree of dominant eye was Center 14.97 sec of arc, Strong 24.45 sec of arc, the dynamic stereoacuity tended to worse when degree of dominant eye was strong. As a result, dominant eye, degree of dominant eye would have to be considered in a more comfortable binocular balance between prescribed for the wearer in binocular vision correction in binocular function such stereoacuity, sports vision training, presbyopia correction and mono vision.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.2
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• pp.179-186
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• 2011

Purpose: This study aimed to compare and assess changes of visual functions in viewing an anaglyph 3D image. Methods: Visual functions were examined before and after viewing a 2D image and an anaglyph 3D image with red-green glasses on seventy college students (mean age = 22.29${\pm}$2.19 years). Visual function tests were carried out for von Graefe phoria test, accommodative amplitude test by (-) lens addition, negative relative accommodation (NRA) and positive relative accommodation (PRA) test, negative relative convergence (NRC) and positive relative convergence (PRC) test, accommodative facility, and vergence facility test. Results: Assessment of the visual functions indicated that near exophoria and accommodative amplitude were reduced after viewing a 3D image, and although there were small changes in relation to these findings, NRC and PRC showed tendencies to increase and decrease at near, respectively. There were no significant changes with NRA and PRA, and accommodative and vergence facility were shown to have improved. Conclusions: Changes of visual functions were more in the 3D image than the 2D image, especially at near than distance. Particularly, the improvement of accommodative and vergence facility could be related to an effect of subsequent accommodation and vergence shift to have stereopsis in the 3D image. These results indicate that an anaglyph 3D image may, to some extent, be the effect of vision training such as anaglyphs.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.281-291
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• 2006

The aim of this study was performed the clinical test using Netspeg lens for good visual acuity on subjects with abnormal refraction status. The subjects of one hundreds adults (fifty males, fifty females, mean=21 years, range=19 to 24) were recorded. The subjects were researched the history including the systemic health, medication, genetics, allergy, systemic disease and ocular disease. The refraction test was recorded the monocular and binocular using objective method. Visual acuity was performed the binocular status using the Netspeg lens and CR-39. Stereopsis test was performed the titmus fly and TNO at near distance using Netspeg lens and CR-39. The P-VEP test was used the 16 pattern size(Bausch Lomb, production in USA) with three channels. Also Subjects viewed the p-vep stimulus with binocular vision through the corrected visual acuity using the Netspeg lens and CR-39. The contrast sensitivity test was performed the contrast sensitivity chart(pelli-Robertson, USA) at 1m distance using the Netspeg lens and CR-39. The ultrastructure of surface on the Netspeg lens and CR-39 was observed the SEM(JMS-5800, made in Japan). The results of this study was as follows: 1. In corrected visual acuity of abnormal refraction using the Netspeg lens and CR-39, the Netspeg lens wearer were acquired the good visual field and clear visual acuity comparative to CR-39 wearer in the subject vision test. however the comfort of visual acuity was similar results in the Netspeg lens and CR-39. Also the subjects of Netspeg lens wearer was good visual acuity more than CR-39 wearer and in the analysis of P-VEP, the amplitude of wave on Netspeg lens used appears to be better through the CR-39(p>0.5). Besides, on the contrast sensitivity, the Netspeg lens wearer was good results than CR-39. The value on stereopsis with TNO by Netspeg lens wearer was better than CR-39 in results. However, in the stereopsis test with Titmus, the Netspeg lens and CR-39 wearer was similar results. 2. The ultrastructure of Netspeg lens surface was the smooth and fine shape more than CR-39. Also, Netspeg lens have a fine line structure in ultrastructure. In conclusion, the results of this study conformed that the surface ultrastructure of Netspeg lens used is more specific pin hole design structure than CR-39. This study indicated that the vision of Netspeg lens used have a better than CR-39 in the corrected visual acuity for abnormal refraction eye. Therefore, In this paper, we suggested that the ultrastructure and line structure of Netspeg lens was related to good visual function. However the visual function of the aspheric Netspeg and ultra waterproof Netspeg lens was similar results.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.2
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• pp.155-160
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• 2010

Purpose: The purpose of this study was to evaluate how phoria variations would vary with head positions, as well as to review the need to differentiate prism placement over either eye in a relation to the imbalance of the extraocular muscle. Methods: This study was carried out with 44 males (88 eyes) and 16 females (32 eyes) aged between 20 and 30. For all subjects, testings were performed using cover test, subjective refraction, phoria and vergence test. To analyze phoria variations comparatively for the head tilt test and the face turn test, phoria deviation were measured using the von Graefe. Results: For the phoria variation related with head tilt and face turn, a significant difference was observed in the group judged to be abnormal on the horizontal phoria of Morgan' norm (p<0.05); especially in patients who needed near prescription of Sheard's criterion, a higher variation was observed (p<0.05). The abnormal group was composed of patients who needed distance prescription of Sheard's criterion and ones who did not need the prescription, all of whom showed phoria variations, but the mean value was less than the near. Conclusions: With regard to the head tilt and face turn related phoria level, the patients who needed near horizontal prism prescription of Sheard's criterion showed a remarkably higher variation. Altogether, it is deemed to check whether extraocular muscles are ill-balanced in both eyes previously to determine the prism power on phoria level to the end that each of prism powers may be accurately determined.