• The Korean Journal of Vision Science
• /
• v.20 no.4
• /
• pp.569-577
• /
• 2018

Purpose : The study looked at how effective each group wearing MyoVison lens, MC lens, and Single Vision lensdepending on their parents' myopia condition. Methods : The study observed the changeof spherical equivalent among customers, who visited between January 2010 and December 2016,of an optical shop in Incheon Metropolitan City. And we observed MyoVision 152 eyes, MC Lens 86 eyes and Single Vision lens 270 eyes. This study was conducted using SPSS ver18, which analyzes the changes in average values of MyoVision, MC Lens, and Single Vision for a year.In each group, the differences in the group were compared using the Paired T-test and then one-way ANOVA (post-hoc; Bonferroni) Results : Group-to-group comparisons showed that MyoVision and MC Lens have a shorterinhibition than Single Vision. In particular, MyoVisionand MC Lens showed different relief effects depending on the degree of refraction of parents.When both parents had normal refractive, the change between MyoVision and Single Vision lens was $-0.35{\pm}0.05D$. When the father had a refraction MC lens were $-0.36{\pm}0.14D$ more effective than Single Vision. When only the mother had refraction, the mean value between MyoVision and Single Vision lens was $-0.37{\pm}0.06D$, and the mean between MC lens and Single Vision lens was $-0.38{\pm}0.08D$. And when both parents had refraction problems, the mean value change between MyoVision and Single Vision lens was $-0.28{\pm}0.07D$, and $-0.31{\pm}0.07D$, respectively. Conclusion : MyoVision and MC Lens appeared to have no effect on the functions of mitigating myopia in within group comparisons, but MyoVision and MC Lens showed reducing myopia than Single Vision in between group.

• Journal of Korean Ophthalmic Optics Society
• /
• v.17 no.1
• /
• pp.19-26
• /
• 2012

Purpose: This paper was to study the clinical effects of moderating myopia by comparing the myopia control lens, which was being recently recognized as a method of inhibiting the progression of myopia, with the wearers of single vision lens. Methods: Using 56 subjects between the ages of 8-15 years (112 eyes) with myopia in the areas of City of Daegu and Gyeongsangbuk Province as study subjects, refractive error, axial length, near point of convergence and accommodative near point were measured and compared a total of 3 times at the baseline, after 1-month and after 6-months. Results: For refractive error, suppression and mitigation were seen in the progression of spherical equivalent when MC lens was worn, as compared to using SV lens, and, when axial length MC lens was worn, the axial progression was significantly suppressed and delayed (p < 0.05). The near point of convergence became shorter with the use of MC lens, and the amplitude of convergence was improved when MC lens was worn. Accommodative near point became shorter with the use of MC lens, and focus ability was significantly improved (p <0.05). Conclusions: It was shown that MC lens, compared to SV lens, could alleviate myopia progression in school-age children and youth. It is considered that MC lens can be used as a useful therapy for the inhibition of myopia progression in the increasing number of myopic children and adolescents.

• Journal of Korean Ophthalmic Optics Society
• /
• v.18 no.1
• /
• pp.75-84
• /
• 2013

Purpose: Changes of refractive correction value in different age group were investigated. Regarding the inhibitive effects against myopia progression after wearing reverse geometry contact lenses and myopia control lenses (MC lenses), the effects after wearing single vision lenses were compared. Methods: We organized children between the ages of six and fifteen into three groups by age, and distributed fifty-seven reverse geometry contact lenses, fifty-six MC lenses and seventy-eight single vision lenses among them to be worn. Group 1 consisted of children aged ten and under, Group 2 consisted of children between the ages of eleven and fifteen, and Group 3 represents all of the study participants. The aim of this study was to learn the inhibitive effects against myopia progression attained by changes of refractive correction value and to verify their statistical significance at twelve months and under, thirteen to twenty-four months and twenty-five to thirty-six months. Results: Changes of refractive correction value by each length of use in Group 3 were as follows. For the age group of under twelve months, participants using the reverse geometric contact lens showed no change, while those using the MC or single vision lens had significant changes (P<0.05) of $-0.36{\pm}0.10$ D and $-0.67{\pm}0.52$ D, respectively. Users of all three lens types displayed significant change (P<0.05), in the age group of between thirteen and twenty-four months, of $0.18{\pm}0.49$ D, $0.60{\pm}0.42$ D and $1.37{\pm}0.72$ D for users of the reverse geometry contact lens, the MC lens and the single vision lens, respectively. There were significant changes (P<0.05) of $0.29{\pm}0.61$ D, $0.93{\pm}0.57$ D and $1.72{\pm}0.78$ in the same respective order as the above in the age group of twenty-five to thirty-six months. Refractive correction value showed changes with different age group. Group 1 displayed significant changes (P<0.05) of $0.29{\pm}0.73$ D, $1.07{\pm}0.59$ D and $1.75{\pm}0.74$ D for users of the reverse geometry contact lens, MC lens and single vision lens, respectively, up to thirty-six months of lens wearing; Group 2, also up to thirty-six months, displayed significant changes (P<0.05) of $0.28{\pm}0.42$ D, $0.75{\pm}0.49$ D and $1.70{\pm}0.84$ D in the same respective order, and changes in refractive correction for the age group under ten years was significantly greater (P<0.05) for the age group of eleven and older. Conclusions: The results found in this study demonstrate that there were no changes of refractive correction value for the case of wearing reversing geometry contact lens up to twelve month or less. MC lens showed less changes in variations of visual acuity for all users which might be resulted in inhibiting progression of myoptia. When both reverse geometry contact lens and the MC lens are wearing for the period from 13 to 36 month, both lens showed less changes in variation of visual acuity for all users. The results suggested that the less changes in variation of visual acuity of both lens had an effect on inhibiting progression of myopia.

• Journal of Korean Ophthalmic Optics Society
• /
• v.12 no.4
• /
• pp.127-131
• /
• 2007

This study was designed to demonstrate the ability of Texas Eye Research and Technology Center Dry Eye Questionaire (TERTC-DEQ) to examine the distribution of self-reported dry eye symptoms and their diurnal intensity in university students and compare it with McMonnies & Ho DEQ. Two dry eye questionnaires were administered to 46 contact lens wearers and 47 nonwearers. Contact lens wearers scored higher on the TERTC-DEQ (52.2%) than McMonnies & Ho DEQ (6.5%). Non-contact lens wearers also scored higher on the TERTC-DEQ (19.1%) than McMonnies & Ho DEQ (2.1%). Ocular symptoms worsened with progression of time of day in both groups of subjects. This study suggests that TERTC-DEQ provides a first-choice diagnosis tool to obtain a comprehensive assessment of patient's symptoms, especially in comparison with McMonnies & Ho DEQ. The TERTC-DEQ is an efficient screening survey and may be use in dry eye diagnosis of contact lens-related dry eye.

• Journal of Korean Ophthalmic Optics Society
• /
• v.9 no.2
• /
• pp.301-312
• /
• 2004

This study was performed to compare the relationship between contact lens wearer and dry-eye patient. In this study, TBUT, SIT, TTT, Rose bengal staining and McMonnies dry eye symptom questionnaire were performed as a baseline. With the base data, the subjects were classified to 3 groups : 3S patients who have dry eye signs and symptoms, 38 patients who are wearing soft contact tenses, 35 subjects who have health eyes and never worn on a contact lenses as control subjects. Contact lens wearers were divided into 3 groups according to the duration of contact lens wear. There were no significant differences in TBUT, STT, TTT, Rose-bengal staining and McMonnies dry eye symptom questionnaire result between contact lens wearer group and dry eye patients group. We suggest that there are similarities in tear function tests between the dry-eye patient and the contact lens wearer.

• Journal of Korean Ophthalmic Optics Society
• /
• v.13 no.3
• /
• pp.19-28
• /
• 2008

Purpose: To understand symptoms and signs in soft contact lens wearers the authors evaluate the attribution of the tear test to the contact lens related symptoms and signs. Methods: Sixty-two healthy soft contact lens wearers (23.95${\pm}$4.38 years old, 18.60${\pm}$16.92 months of prior lens wear) were participated in this study. 3 kinds of tear test and McMonnies' questionnaire test were performed for the soft contact lens wearers and subjective symptoms and objective signs were graded using CCLRU scales during the study period. Results: In this surveys, we found ocular dryness, redness and tiredness are the most common frequent and severe symptoms in soft contact lens wearers. Frequency of the ocular dryness, redness and tiredness are associated with grittiness, burning sensation and foreign body sensation respectively, and severity of the photophobia, foreign body sensation are associated with unstable vision and grittiness and which are associated with score of McMonnies' Questionnaire. Conjunctival redness and limbal redness are major signs but those are not need to be clinical care and rarely occurred corneal and conjunctival staining which are associated with tear break-up-time statistically. Conclusions: Dryness, redness and tiredness are primary common symptoms in Korean soft contact lens wearers. The frequency of those symptoms are increased with the period of soft contact lens wear and those are associated with other symptoms but have no relationship with signs.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.262-262
• /
• 2012

A multi-purpose cyclotron, MC50 has been operated to provide multi-ions of proton, deuteron and alpha at Korea Institute of Radiological and Medical Sciences (KIRAMS). Neutron is also produced through the (p,n) nuclear process with a Be target. However, a wide spectrum of current of ions is requested by beam users for carrying their various application fields. Therefore a simulation study is requested on the design of an axial injection system for high current proton and alpha beam extraction for radio-isotope productions and scientific researches. The purpose of this study is seeking a relatively simple method for the MC50 having higher alpha beam capability and also improving proton and deuteron beams currently used. We are considering two possibilities to improve the internal ion source and to install a new external axial injection system. The external injection system will be consisted of an Einzel lens, a steering magnet, a buncher, and a glazer lens placed in front of an inflector, which is located at the center of the main magnet.

• Journal of Industrial and Engineering Chemistry
• /
• v.67
• /
• pp.236-243
• /
• 2018

A series of $Er^{3+}/Yb^{3+}$ co-doped fluorophosphate glasses with varying $YbF_3$ concentration were prepared by a high temperature melt quenching technique. Absorption and emission cross-sections were determined by using the McCumber theory. The larger emission cross-section ($9.86{\times}10^{-21}cm^2$) and longer fluorescence lifetime (12.37 ms) were obtained for the $^4I_{13/2}{\rightarrow}^4I_{15/2}$ transition of ABS3Er4Yb glass. The sensitivity and temperature of the maximum sensitivity were evaluated by the fluorescence intensity ratio method from the measured upconversion spectra. The results were discussed and compared to the other reported glasses.

• The Bulletin of The Korean Astronomical Society
• /
• v.35 no.1
• /
• pp.36.2-36.2
• /
• 2010

The CQUEAN (Camera for QUasars in EArly uNiverse) is an optical CCD camera optimized for observation of high redshift objects. It is going to be attached to the cassegrain focus of 2.1m telescope at McDonald Observatory, USA. We are making a focal reducer for CQUEAN to secure a larger field of view. The focal reducer is composed of four spherical lens, and it reduces the focal length of telescope by one third. We designed the lens configuration, performed tolerance analysis, and estimated the optical performance with ZEMAX. The differences in optical performace with/without filters were also investigated. The result from ZEMAX shows that the system has ample margin of errors for median seeing of 1.2" at McDonald observatory. Even with aberration and alignment tolerance, the performance is better than the original requirement. The lenses are now being made, and the lens barrel and an adapter for assembly of the Andor CCD camera and the filter wheel is now under designing process. We expect that the manufacturing of the focal reducer system as well as its optical test will be finished by April 2010.

• Journal of Integrative Natural Science
• /
• v.11 no.1
• /
• pp.39-43
• /
• 2018

Poly(hydroxyethyl methacrylate)-based hydrogels were surface-functionalized with spiropyran (SP) derivatives to obtain photochromic contact lenses. The contact lens reversibly changes from colorless to purple as response to UV light since colorless ring-closed SP state converts to purple ring-opened merocyanine (MC) state under UV light irradiation. The purple contact lens emits red light at 640 nm. Importantly, the presence of SP segments did not significantly affect the equilibrium water content (EWC) of the lens. SP-functionalized hydrogel lenses may find potential applications in developing light-adaptive ophthalmic materials.