• 지역사회간호학회지
• /
• 제25권4호
• /
• pp.259-269
• /
• 2014

Purpose: The purpose of this study was to examine dry eye syndrome and ocular fatigue according to the status of contact lens wearing and management among female university students. Methods: The subjects were 195 female university students wearing contact lenses. Ocular Surface Disease Index (OSDI) and Virtual Reality Symptom Questionnaire (VRSQ) were used to determine the level of dry eye syndrome and ocular fatigue. The SPSS/WIN 21.0 program was used for analysis of data. Results: Significant differences in the level of dry eye syndrome were observed according to the period of case solution change (F=3.36, p=.037) and the reasons for the change of lens (F=4.56, p=.004). In ocular fatigue, significant differences were observed according to the price of lens (F=3.53, p=.031), rinse in storing lens in a case (t=-2.57, p=.011), and learning about contact lens (t=-2.01, p=.046). A significant positive correlation was observed between dry eye syndrome and ocular fatigue in the subjects. Conclusion: The results of this study show that some subjects have problems in wearing and management of contact lenses. Therefore, an education program related to contact lenses should be provided to contact lens wearers to improve the status of wearing and management of contact lenses.

• 한국안광학회지
• /
• 제10권3호
• /
• pp.221-228
• /
• 2005

현재 국내에서 유통되고 있는 국내외 렌즈제품들을 대상으로 굴절력과 중심부 두께의 측정을 통해 제품간의 차이를 분석하였다. 국내 제품들은 해외제품에 버금갈 정도로 제작되었지만 허용기준에 맞지 않는 경우가 있었으며, 또 통일 제품들에서도 차이를 줄일 필요가 있다. 국내제품들이 해외 제품들에 비해 더 경쟁력을 가지기 위해서는 전문인력의 육성, 엄격한 품질검사, 공정관리, 규격의 표준화가 필요하다.

• 한국안광학회지
• /
• 제10권2호
• /
• pp.133-138
• /
• 2005

비구면렌즈는 구면렌즈계의 단점을 보완하여 결상 성능을 향상시키며, 렌즈의 사용매수를 경감시키고 이로 인하여 광학계의 무게와 부피를 줄이는 소형경량화를 목적으로 하여 사용되고 있다. 비구면 광학소자의 생산기술과 측정기술은 현대의 첨단기술로 부각되고 있다. 비구면으로 구성된 원광학계는 넓은 시야와 고성능, 양질의 상을 얻을 수 있고, 또한 소형, 경량화 시킬 수 있는 등 많은 장점을 가지고 있다. 이러한 비구면 소자의 급증하는 필요성에 부응하여 비구면 가공 기술과 측정 기술에 대하여 연구하고자 한다. 비구면 생산 기술과 측정 및 평가 기술은 끊임없이 발전하고 있음을 밝혀둔다.

• Design & Manufacturing
• /
• 제1권1호
• /
• pp.27-32
• /
• 2007

In the optical application demand for high quality lens is increasing. Plastics lenses are demanded more than glass lenses for large size lenses as well as micro-size lenses. It is difficult to apply typical straight cooling channels of injection mold to lens molding due to its non-uniform temperature distribution. In this study, we manufactured molds for plastic lenses with the conventional cooling channels and conformal cooling channels produced by the DMLS process. We evaluated cooling performance for the 2 molds by injection molding experiment. Also, uniformity of the temperature distribution was tested by infrared camera and temperature monitoring. We confirmed that the cooling performance and temperature uniformity with the conformal cooling channels is much improved from the ones with the conventional. The cooling time with the conformal cooling channels was reduced 30% compared with the conventional cooling channels.

• 정보저장시스템학회논문집
• /
• 제1권2호
• /
• pp.121-126
• /
• 2005

Recently, an optical disc system has been proposed using blue laser diode, high NA objective lens and groove only disc structure. A new method is needed to readout CD and DVD in this Blu-Ray Disc Recorder. In order to readout CD and DVD in Blu-Ray Disc Recorder, we adopted dual-lenses actuator in consideration of optical utilization efficiency, optical performance and insurance of sufficient W.D(working distance). This dual-lenses actuator has two objectives in radial direction, one is for CD/DVD and the other is for BD. We had to solve the induced problems of collision between disc and lens, DC tilt increase, AC tilt increase, 2nd resonance deterioration and AC sensitivity drop caused by disposing two lenses in an actuator. Also we developed high response twin- objective actuator with radial tilt function to apply high-speed BD Recorder or BD Player. Consequently we presented that two kinds of dual-lenses actuators for BD Recorder have been possessed good performance in 3 axis directions. And we measured eye patterns of CD, DVD and BD by using one BD optical pick-up with dual-lenses actuator.

• 한국금형공학회:학술대회논문집
• /
• 한국금형공학회 2008년도 하계 학술대회
• /
• pp.143-148
• /
• 2008

In order to produce high-quality optical components, aspheric lenses have been widely applied in recent years. An aspheric lens consists of aspheric surfaces instead of spherical ones, which causes difficulty in the design process as well as the manufacturing procedure. Although injection molding is widely used to fabricate optical lenses owing to its high productivity, there remains lots of difficulty to determine appropriate mold design factors and injection molding parameters. In the injection molding fields, computer simulation has been effectively applied to analyze processes based on the shell analysis so far. Considering the geometry of optical lenses, a full-3d simulation based on solid elements has been reported as a reliable approach. The present work covers three-dimensional injection molding simulation and relevant deformation analysis of an injection molded plastic lens based on 3d solid elements. Numerical analyses have been applied to the injection molding processes of three aspheric lenses for an image sensing module of a mobile phone. The reliability of the proposed approach has been verified in comparison with the experimental results.

• 소성∙가공
• /
• 제20권5호
• /
• pp.333-338
• /
• 2011

Rapidly developing IT technologies in recent years have raised the demands for high-precision optical lenses used for sensors, digital cameras, cell phones and optical storage media. Many techniques are required to manufacturing high-precision optical lenses, including multi-beam sensing lenses investigated in the current study. In the case of injection molding for thick lenses, a shrinkage phenomenon often occurs during the process. This shrinkage is known to be the main reason for the lower optical quality of the lenses. In the present work, a CAE analysis was conducted simultaneously with experiments to understand and minimize this phenomenon. In particular, the sectional area of a gate was varied in order to understand the effects of packing and cooling processes on the final shrinkage pattern. As a result of this study, it was demonstrated that a dramatic reduction of the shrinkage could be obtained by increasing the width of the gate.

• 한국임상보건과학회지
• /
• 제7권1호
• /
• pp.1205-1214
• /
• 2019

Purpose: To investigate the effect of color soft contact lenses on the corneal thickness in young Korean population. Methods: The subjects consisted of 112 eyes (7 males, 49 females) with the mean age of $20.987{\pm}1.093years$ (range 20-25 years) in young Korean population during 2018. Test was compared the corneal thickness before and after wearing color soft contact lenses. The thinnest cornea thickness(TCT), central cornea thickness(CCT), pupil centre thickness(PCT), superior corneal thickness(SCT),inferior corneal thickness(ICT), medial corneal thickness(MCT), lateral corneal thickness(LCT) of the cornea was measured using the Pentacam pachymetry. The statistically analysis was perform the Shaparo-Wilk test. Results: The right eye was a statistically significant among the CCT,LCT, MCT and TCT values(p<0.001) in the compared the corneal thickness before and after wearing soft colour contact lenses. Also the left eye was a statistically significant among the LCT and MCT values(p<0.001) in the compared the corneal thickness before and after wearing soft colour contact lenses. However, there was no statistical difference (p>0.5) in the mean PCT between before and after wearing color soft contact lenses. Conclusion: These results suggested that the color soft contact lens wear can the effect the regional thickness of cornea. Therefore, the analysis of corneal topography with Pentacam can provide correct and useful diagnostic information of the morphology of the RGP contact lens fitting and diagnosis of corneal refraction surgery.

• 한국안광학회지
• /
• 제21권1호
• /
• pp.1-10
• /
• 2016

목적: 본 연구는 60대 이상의 노년층을 대상으로 착색안경렌즈의 처방이 시력교정의 질에 미치는 영향을 평가하고 가장 효과적인 착색렌즈의 색상을 제시하고자 하였다. 방법: 60대 이상(평균 $71.0{\pm}6.3$세)의 50명(남17, 여33)을 대상으로 원거리 시력이 0.5 이상이 되도록 시험테를 이용하여 교정한 후 무착색, 브라운착색 및 그레이착색렌즈를 덧댐하였다. 각각 착색안경렌즈 덧댐 시의 시력은 원거리 최소가독시력 및 최소분리시력을 측정한 후 LogMAR 시력으로 환산하여 비교하였으며, 시기능은 근거리 입체시와 대비감도를 측정하여 비교하였다. 또한 대상자들의 착색안경렌즈 선호도와 시지각 및 움직임에 대한 자각증상을 설문조사하였다. 결과: 원거리 최소가독시력과 최소분리시력은 무착색렌즈의 사용 시 가장 좋았으며, 브라운착색 및 그레이착색렌즈 순으로 나타났다. 근거리 입체시, 대비감도 및 시지각은 브라운착색렌즈의 사용 시 가장 좋은 것으로 나타났다. 자각적 불편감은 그레이착색렌즈 착용 시 가장 크게 나타났으며, 대상자가 선호하는 안경렌즈는 브라운착색렌즈로 조사되었다. 결론: 이상의 결과로 착색안경렌즈의 사용으로 노년층의 시력과 시기능이 개선될 수 있으나, 시력 및 시기능의 변화가 자각적 만족도와는 반드시 일치하는 것은 아님을 알 수 있었다. 본 연구결과, 1,000 lux정도의 조도에서는 원거리 시생활이 보편화된 노년층에게는 무착색 및 브라운착색렌즈의 사용을, 근거리 작업이 많은 경우에는 브라운 및 그레이착색렌즈의 사용을 제안할 수 있겠다.

• 천문학논총
• /
• 제32권1호
• /
• pp.251-255
• /
• 2017

Submillimetre and millimetre-wave surveys with Herschel and the South Pole Telescope have revolutionised the discovery of strong gravitational lenses. Their follow-ups have been greatly facilitated by the multi-wavelength supplementary data in the survey fields. The forthcoming Euclid optical/near-infrared space telescope will also detect strong gravitational lenses in large numbers, and orbital constraints are likely to require placing its deep survey at the North Ecliptic Pole (the natural deep field for a wide class of ground-based and space-based observatories including AKARI, JWST and SPICA). In this paper I review the current status of the multi-wavelength survey coverage in the NEP, and discuss the prospects for the detection of strong gravitational lenses in forthcoming or proposed facilities such as Euclid, FIRSPEX and SPICA.