• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.579-588
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• 2018

Purpose : To analyze the eyeglasses supply system for ametropic soldiers in ROK military. Methods : We investigated and analyzed the supply system of eyeglasses for the ametropic soldiers provided by the Korean military. The refractive powers and corrected visual acuity were measured for 37 ametropic soldiers who wear insert glasses for ballistic protective and gas-masks supplied by the military based on their habitual prescriptions. Full correction of refractive error was prescribed for subjects having less than 1.0 of distance visual acuity, and comparison was held for inspecting the changes in corrected visual acuity. Suggestions were provided for solving the issues regarding current supplying system, and this study investigated the applicabilities for utilizing professional optometric manpower. Results : The new glasses supplied by army for ametropic soldiers were duplicated from the glasses they worn when entering the army. The spherical equivalent refractive powers of the conventional, ballistic protective and gas-mask insert glasses supplied for 37 ametropic soldiers were $-3.47{\pm}1.69D$, $-3.52{\pm}1.66D$ and $-3.55{\pm}1.63D$, respectively, and the spherical equivalent refractive power of full corrected glasses was $-3.79{\pm}1.66D$, which showed a significant difference(p<0.05). The distant corrected visual acuity measured at high and low contrast(logMAR) of conventional, ballistic protective and gas-mask insert glasses were $0.06{\pm}0.80$, $0.21{\pm}0.82$, $0.15{\pm}0.74$, $0.34{\pm}0.89$, $0.10{\pm}0.70$ and $0.22{\pm}0.27$, respectively, while the corrected visual acuity by full corrected glasses were increased to $0.02{\pm}1.05$, $0.10{\pm}0.07$, $0.09{\pm}0.92$, $0.26{\pm}0.10$, $0.04{\pm}1.00$ and $0.19{\pm}1.00$, respectively. There was a significant difference(p<0.05) except for the case of the low contrast corrected visual acuity of the conventional and gas-mask insert glasses. The procedure for ordering, dispensing, and supplying military glasses consists of 5 steps, and it was found that approximately two weeks or more are required to supply from the initial examination. Conclusion : The procedure of supplying the military glasses showed three issues: 1) a lack of refraction for prescription system, 2) relatively long length of time required for supplying the glasses, 3) an inaccurate power of supplied glasses. In order to solve those issues, in the short term, education is necessarily required for soldiers on the measurement of the refractive powers, and in the near future, further standard procedures for prescription of glasses as well as the securement of optometric manpower are expected.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.4
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• pp.391-401
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• 2011

Purpose: In the present study, the actual management state of trial contact lenses and lens care products in local optical shops was surveyed and analyzed to reduce the risk of lens complication possibly induced by neglecting lens care. Methods: The feeling of contact lens wearers during the wear of trial contact lenses was surveyed. Futhermore, the actual management state of trial contact lenses such as cosmetic lens and RGP lens and lens care products was also investigated by surveying opticians who trade contact lenses in local optical shops. Results: It was found that consumers trusted the sanitary conditions of the lens since trial cosmetic contact lens and RGP lens were cleaned before and after trails by over 98% of opticians in local optical shops. For trial cosmetic lens, cleaning with normal saline, multipurpose solution for soft lens and combination of saline and multipurpose solution were 38.5%, 40.5% and 21%, respectively, before trials. After trials, cosmetic lenses were cleaned with normal saline, multipurpose solution for soft lens and a combination of saline and multipurpose solution were 13%, 75%, and 12%, respectively. On the other hand, cleaning with normal saline, multipurpose solution for RGP lens and combination of saline and multipurpose solution were 28.5%, 38.5% and 33%, respectively, before trying trial RGP lens. After trials, RGP lenses were cleaned with normal saline, multipurpose solution for RGP lens and a combination of saline and multipurpose solution were 2.5%, 70%, and 27.5%, respectively, indicating that relatively many opticians followed the lens cleaning regimen. In local optical shops, the cleaning trial cosmetic lens was mainly conducted at every 10 days or a month and the washing cycle of cosmetic lens case was in a month or 2~3 months. The cleaning interval of trial RGP lens was primarily in a month or 2~3 months. For those lens cases, more than 75% of opticians washed them with a surfactant and then rinsed with cold water. The storing periods of lens care products were primarily in a week for saline and in a month and 2~3 months indicating that storing period of lens care products was relatively well-kept in local optical shops. Conclusions: It is thought that the concern about any microbial infection is not that high since trial contact lenses and lens care products were generally well-managed by opticians in local optical shops from the results above. However, better public eye health and better public confidence in opticians may be possible if further strengthen in avoidance of lens cleaning with saline, keep of cleaning cycles within 2 weeks and rinsing of lens cases with hot water happens.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.217-223
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• 2006

The purpose of this study is to provide improvements and standards of trial lens, in a situation that there is a lack of standards of trial lens set that have been used for self-conscious refraction test after helm refraction test at about 5,000 opticians, ophthalmologic clinics and hospitals, and contact-lens shops, that there is a lot of discrepancies between refraction specified and the actual power, and that there is no regulation of optical tolerance error. For the study, opticians who have used Trial lens set were asked to participate in a questionnaire survey through continuing education, and divided into those who have used domestic lens and those who have used imported lens, 5 opticians each for less than 5 years, 5 to 10 years, more than 10 years. The measurement of both refraction specified and the actual diopter was compared to Japan Industrial Standards(JIS T4402). As a result of comparative analysis, more than 80% of respondents have had reliability on the refraction of trial lens they had used, indicating that they have never measured the refraction specified and the actual diopter after buying them. Besides, Korean Industrial Standards(KS P4402) has been imperfect in diopter range since it was legislated in 1979. More than 95% of respondents have been unsatisfied with optometry. Also, it has indicated that refraction error is more frequent in long-term-used trial lens. The conclusion is that it is necessary to standardize trial lens set and that it is required to add lens to lens set provided under KS P4402. Moreover, it is necessary to have supervisory agency for a standardization of trial lens. I hope that both domestic lens and imported lens, as in German and Japan, will be tested to find whether they meet optical tolerance error and standard trial lens will be distributed. Good optic inspection is required for the improvement and management of eye health and optical function, and the same standard trial lens set should be used. whoever is tested. Also, I hope that trial lens set will be specified within standards and tolerance error.

• 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.

• Radiation Oncology Journal
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• v.20 no.1
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• pp.1-16
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• 2002

Purpose : Three dimensional conformal radiotherapy planning is being used widely for the treatment of patients with brain tumor. However, it takes much time to develop an optimal treatment plan, therefore, it is difficult to apply this technique to all patients. To increase the efficiency of this technique, we need to develop standard radiotherapy plant for each site of the brain. Therefore we developed several 3 dimensional conformal radiotherapy plans (3D plans) for tumors at each site of brain, compared them with each other, and with 2 dimensional radiotherapy plans. Finally model plans for each site of the brain were decide. Materials and Methods : Imaginary tumors, with sizes commonly observed in the clinic, were designed for each site of the brain and drawn on CT images. The planning target volumes (PTVs) were as follows; temporal $tumor-5.7\times8.2\times7.6\;cm$, suprasellar $tumor-3\times4\times4.1\;cm$, thalamic $tumor-3.1\times5.9\times3.7\;cm$, frontoparietal $tumor-5.5\times7\times5.5\;cm$, and occipitoparietal $tumor-5\times5.5\times5\;cm$. Plans using paralled opposed 2 portals and/or 3 portals including fronto-vertex and 2 lateral fields were developed manually as the conventional 2D plans, and 3D noncoplanar conformal plans were developed using beam's eye view and the automatic block drawing tool. Total tumor dose was 54 Gy for a suprasellar tumor, 59.4 Gy and 72 Gy for the other tumors. All dose plans (including 2D plans) were calculated using 3D plan software. Developed plans were compared with each other using dose-volume histograms (DVH), normal tissue complication probabilities (NTCP) and variable dose statistic values (minimum, maximum and mean dose, D5, V83, V85 and V95). Finally a best radiotherapy plan for each site of brain was selected. Results : 1) Temporal tumor; NTCPs and DVHs of the normal tissue of all 3D plans were superior to 2D plans and this trend was more definite when total dose was escalated to 72 Gy (NTCPs of normal brain 2D $plans:27\%,\;8\%\rightarrow\;3D\;plans:1\%,\;1\%$). Various dose statistic values did not show any consistent trend. A 3D plan using 3 noncoplanar portals was selected as a model radiotherapy plan. 2) Suprasellar tumor; NTCPs of all 3D plans and 2D plans did not show significant difference because the total dose of this tumor was only 54 Gy. DVHs of normal brain and brainstem were significantly different for different plans. D5, V85, V95 and mean values showed some consistent trend that was compatible with DVH. All 3D plans were superior to 2D plans even when 3 portals (fronto-vertex and 2 lateral fields) were used for 2D plans. A 3D plan using 7 portals was worse than plans using fewer portals. A 3D plan using 5 noncoplanar portals was selected as a model plan. 3) Thalamic tumor; NTCPs of all 3D plans were lower than the 2D plans when the total dose was elevated to 72 Gy. DVHs of normal tissues showed similar results. V83, V85, V95 showed some consistent differences between plans but not between 3D plans. 3D plans using 5 noncoplanar portals were selected as a model plan. 4) Parietal (fronto- and occipito-) tumors; all NTCPs of the normal brain in 3D plans were lower than in 2D plans. DVH also showed the same results. V83, V85, V95 showed consistent trends with NTCP and DVH. 3D plans using 5 portals for frontoparietal tumor and 6 portals for occipitoparietal tumor were selected as model plans. Conclusion : NTCP and DVH showed reasonable differences between plans and were through to be useful for comparing plans. All 3D plans were superior to 2D plans. Best 3D plans were selected for tumors in each site of brain using NTCP, DVH and finally by the planner's decision.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.39-48
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• 2007

The stimulus of accommodation A, the stimulus of convergence C and the prism diopter ${\Delta}$ are reviewed and redefined more obviously. How the A and C are managed in the practice are reviewed and summarized. As a result, the common practical process of the binocular vision findings is most suitable in the case of the $l_c=26.67mm$, where the near distance is measured from the test lens to the near target and its value is 40 cm and the average of the P.D equal to 64 mm. The $l_c$ is the distance between the test lens and the center of rotation. Those values were used at calculating the various values in this paper. The error of the stimulus of accommodation values which are evaluated by the practically used formula (5) are calculated. Where the distance between lens and the principle point of eye is 15.07 mm ($=l_H$). The incremental stimulus of convergence values P' caused by the addition prism $P_m$ are evaluated by the recursion computation method. The P' are varied with the $P_m$, the distance $p_c$ between the prism and the center of rotation, the initial convergence value (or inverse target distance) $C_o$ and the refractive index n of the prism material. The recursion computation method and the other formulas are described in detail. In this paper n=1.7 is used. The two factors by which the P' is increased are exist. The one which is major is the property by which the values of convergence whose unit is ${\Delta}$ are not added in the generally way. The other is the that the actual power of the prism is varied with the angle of incidence light. And the P' is decreased remarkably by an increase in the $p_c$ and $C_o$. The $P^{\prime}/P_m$ are calculated and graphed which are varied with the $p_c$ and $C_o$, where the $P_m=20{\Delta}$, P.D=64 mm and n=1.7. The index n dependence of the $P^{\prime}/P_m$ is negligible (refer to fig. 6). The $p_c$ are evaluated at which the P' equal to the $P_m$ for various $P_m$ (refer to table 1). The actual values of the stimulus of convergence and accommodation which are manipulated simply in the practice are calculated. Two graphical forms are suggested. The one is like as the commonly used one. But the stimulus of convergence and of accommodation values in the practice are positioned at the exact positions when the graphic is made (refer to fig. 9). The other is the form that the incremental stimulus of convergence values caused by the addition prisms are represented at actual positions (refer to fig. 11).

• Journal of Korea Water Resources Association
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• v.53 no.10
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• pp.845-859
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• 2020

Climate change and recent heat waves have drawn public attention toward other environmental issues, such as water pollution in the form of algal blooms, chemical leaks, and oil spills. Water pollution by the leakage of chemicals may severely affect human health as well as contaminate the air, water, and soil and cause discoloration or death of crops that come in contact with these chemicals. Chemicals that may spill into water streams are often colorless and water-soluble, which makes it difficult to determine whether the water is polluted using the naked eye. When a chemical spill occurs, it is usually detected through a simple contact detection device by installing sensors at locations where leakage is likely to occur. The drawback with the approach using contact detection sensors is that it relies heavily on the skill of field workers. Moreover, these sensors are installed at a limited number of locations, so spill detection is not possible in areas where they are not installed. Recently hyperspectral images have been used to identify land cover and vegetation and to determine water quality by analyzing the inherent spectral characteristics of these materials. While hyperspectral sensors can potentially be used to detect chemical substances, there is currently a lack of research on the detection of chemicals in water streams using hyperspectral sensors. Therefore, this study utilized remote sensing techniques and the latest sensor technology to overcome the limitations of contact detection technology in detecting the leakage of hazardous chemical into aquatic systems. In this study, we aimed to determine whether 18 types of hazardous chemicals could be individually classified using hyperspectral image. To this end, we obtained hyperspectral images of each chemical to establish a spectral library. We expect that future studies will expand the spectral library database for hazardous chemicals and that verification of its application in water streams will be conducted so that it can be applied to real-time monitoring to facilitate rapid detection and response when a chemical spill has occurred.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.2
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• pp.51-57
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• 2008

Purpose: This study has been conducted to know how the size and position of the circle of least confusion has an influence on the vision for minimization of asthenopia when astigmatism is corrected and appropriated prescription to provided clear vision life. Methods: The method of the study has been worked on 68 students (136 eyes) of man and woman enrolled in university of Gyeong-gi-do aged 20 to 40, who have myopic astigmatism in order to know how the corrected vision changes according to the size and position of the circle of least confusion of astigmatism, the vision has been tested by giving the vision whose astigmatic power of 0.25D and 0.50D was just reduced, low correcting the astigmatic power into 0.50D, and at the same time inserting additionally spherical power -0.25D, all under a condition that the corrected vision after completely corrected astigmatism, and the axis of astigmatism was not changed. Results: The average vision was 1.047 when the astigmatic power was fully corrected, and in low correction of 0.25D, it was 0.914, and in low correction of 0.50, it was 0.772. It has been learned that the bigger the circle of least confusion was the bigger the range of vision reduction and the corrected vision in astigmatism has correlation with the size of the circle of least confusion. It has been examined that the average vision according to position of the circle of least confusion in astigmatism was 1.047 when the astigmatic power was completely corrected and focused on the retina with state of point, and in case that the astigmatic power was 0.50D of state of low correction, that is, the circle of least confusion was focused before retina, it was 0.828, and it was also 0.826 when the astigmatic power is low corrected with 0.50D and the circle of least confusion was focused on the retina. Explained briefly, It has been examined that in case that the state of low correction of the astigmatic power was same, the vision reduction was less in the image of the circle of least confusion focused upon the retina than in the image of its being focused before the retina. Conclusions: In case that the refractive power of cylindrical lens is reduced in test of wearability in astigmatism, there needs surely an adjustment of spherical lens that can place the circle of least confusion on the retina.

• Journal of Life Science
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• v.31 no.2
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• pp.126-136
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• 2021

Oxidative stress causes injury to and degeneration of retinal pigment epithelial (RPE) cells. It is involved in several retinal disorders and leads to vision loss. In the present study, we investigated the effect of 14 kinds of natural compounds and two kinds of synthetic compounds on oxidative stress-induced cellular damage in human PRE cell lines (ARPE-19). From among them, we selected five kinds of compounds, including auranofin, FK-509, hemistepsin A, honokiol, and spermidine, which have inhibitory effects against hydrogen peroxide (H2O2)-mediated cytotoxicity. In addition, we found that four kinds of compounds (excluding auranofin) have protective effects on H2O2-induced mitochondrial dysfunction. Furthermore, the expression of phosphorylation of histone H2AX, a sensitive marker of DNA damage, was markedly up-regulated by H2O2, whereas it was notably down-regulated by FK-506, honokiol, and spermidine treatment. Meanwhile, five kinds of candidate compounds had no effect on H2O2-induced intracellular reactive oxygen species (ROS) levels, suggesting that the five candidate compounds have protective effects on oxidative stress-induced cellular damage through the ROS-independent pathway. Taken together, according to the results of H2O2-mediated cellular damage―such as cytotoxicity, apoptosis, mitochondrial dysfunction, and DNA damage―spermidine and FK-506 are the natural and synthetic compounds with the most protective effects against oxidative stress in RPE. Although further studies on the identification of the mechanism responsible are required, the results of the present study suggest the possibility of using spermidine and FK-506 to suppress the risk of retinal disorders.

• The Southeast Asian review
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• v.28 no.1
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• pp.21-51
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• 2018

This article takes several approaches in explaining recent developments in Vietnam. First, it draws upon an array of sources that idealize Vietnam's embrace of capitalism and integration into the global market in order to sketch out its economy's progress in 2017. Second, it observes, evaluates, and diagnoses recent changes in the Vietnamese economy in the medium to long term by incorporating conflicting perspectives on Vietnam's performance as a capitalist country. Third, this article traces the power shifts that have risen from internal struggles in the Communist Party over political and social issues. Fourth, it elaborates on the aforementioned impact that foreign relations have had on socio-political developments in Vietnam, as well as the government's response. In so doing, it also attempts to evaluate, however briefly, the significance of the 25th anniversary of South Korea-Vietnam relations. Finally, it examines the public's reaction to the post-reform transitions in light of recent sociocultural changes. 2017 was a memorable year for Vietnam: a continuous march toward capitalism; the resulting expansion of the Vietnamese people's demands; political controversies and government control; the looming instability of United States-China relations and various attempts to address the situation. These events will inevitably replicate themselves in the future as the ostensibly socialist Vietnam adopts a capitalist model. The problem is that it is unclear whether these experiences will continue with the consent of the people of socialist Vietnam or engender resistance. It is difficult to achieve meaningful consent in the status quo of worsening inequalities, widespread corruption, monopoly on power, and sustained use of unskilled low-wage workers. In other words, when concerns such as welfare, public health, and the environment are set aside in favor of economic development and commercialization as they have been, discontent, rather than consent, will prevail. It is thus important to keep a watchful eye on the viability of the nominal economic growth, surface-level political stability, and strategic responses to foreign relations that took place in 2017.