• Journal of Environmental Health Sciences
• /
• v.21 no.4
• /
• pp.75-86
• /
• 1995

This study was performed to investigate the negative side effects of video display terminal (VDT) work on the human body and to provide data for preventing VDT syndrome. A questionnaire survey was made to 339 VDT workers at 22 offices in Taegu, Kyungpook and Kyungnam areas from July 1 to August 31, 1994, and 280 of them were finally used for statistical analysis. The VDT syndrome in the present study inclhded five factors, namely as eye-related symptom, psychological symptom, general body symptom, musculoskeletal symptom, and skin-related symptom, and the estimates of Crombach coefficients of the five factors were 0.954, 0.952, 0.953, 0.957, and 0.955, respectively, showing very high reliability. In view of socio-economical characteristics, the symptoms of female were higher than those of male in the order of musculoskeletal symptom, eye-related symptom, skin-related symptom and psychological symptom. The age group of 30 years or less was higher than the older groups in the order of musculoskeletal symptom, eye-related symptom, psychological symptom and skinrelated symptom. The group of lower education level showed higher skin-related symptom. The psychological symptom and skin-related symptom increased as the amount of smoking increased. Higher eye-related symptom was observed in the group without glasses. In the job-related variables, the group of working on programming and data input showed higher eye-related symptom and psychological symptom. The group of working on programming and graphic design showed higher musculoskeletal symptom and skin-related symptom. The skin-related symptom increased as the total time of VDT operation per day increased. The group of working 2-4 hours followed by 15 minutes rest was higher in musculoskeletal symptom and psychological symptom. Higher musculoskeletal symptom was observed from the group working on Friday and Sunday. The group of 1 year or less working showed higher in skin-related symptom. In relation with the VDT type, all symptoms except skin-related symptom were higher in the group using monochrome monitor. As showed above, the questionnaire could be a tool for evaluating VDT syndrome and prevention of the syndrome would be possible by a comprehensive consideration of factors including socio-economic characteristics, job-related variables and VDT type.

• Journal of Digital Contents Society
• /
• v.7 no.1
• /
• pp.67-74
• /
• 2006

In current video-conferencing systems. user's face movements are restricted by fixed camera, therefore it is inconvenient to users. To solve this problem, tracking of face movements is needed. Tracking using whole face needs much computing time and whole face is difficult to define as an one feature. Thus, using several feature points in face is more desirable to track face movements efficiently. This paper addresses an effective eye location algorithm which is essential process of automatic human face tracking system for natural video-conferencing. The location of eye is very important information for face tracking, as eye has most clear and simplest attribute in face. The proposed algorithm is applied to candidate face regions from the face region extraction. It is not sensitive to lighting conditions and has no restriction on face size and face with glasses. The proposed algorithm shows very encouraging results from experiments on video-conferencing environments.

• Journal of The Korean Association For Science Education
• /
• v.36 no.4
• /
• pp.705-715
• /
• 2016

The purpose of this research is to analyze elementary students' attention characteristics through attention test and eye tracking on real science classes. The SMI's ETG(eye tracker glasses) mobile eye tracker was used to analyze the attention process of elementary students'. The sampling rate of the ETG is 30Hz. The participants of attention test were elementary 155 6th-grade elementary students and the participants for the eye-tracker were six 6th-grade male students. The eye movements were analyzed using the 'BeGaze Mobile Video Analysis Package' program. The results of this research are as follows. First, the attention test results of elementary students showed high correlation between selective attention and sustained attention (.85) and low correlation between selective attention and self-regulation (.32). Second, the attention types of elementary students were divided into four; attention, inattention, easygoing and hasty. Third, elementary students' attention were divided into top-down, bottom-up, default mode network through analysis of elementary students′ eye-movements during real science classes. Also their attention shift occurred frequently due to various reasons in real class situation. There were three reasons that made elementary students fail to handle knowledge-dependent top-down attention; 1) the cognitive failure of target caused by failing to focus attention, 2) the absence of prior knowledge on target object, 3) the analogical failure of prior knowledge. Finally, elementary students' attention process were schematized based on the analysis of students' eye movements and attention test. This research is expected to be utilized as basic data for developing effective teaching strategies, teaching-learning models and instructional materials.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.44 no.1
• /
• pp.56-63
• /
• 2007

In this paper, an eye tracking method is presented using a neural network (NN) and mean-shift algorithm that can accurately detect and track user's eyes under the cluttered background. In the proposed method, to deal with the rigid head motion, the facial region is first obtained using skin-color model and con-nected-component analysis. Thereafter the eye regions are localized using neural network (NN)-based tex-ture classifier that discriminates the facial region into eye class and non-eye class, which enables our method to accurately detect users' eyes even if they put on glasses. Once the eye region is localized, they are continuously and correctly tracking by mean-shift algorithm. To assess the validity of the proposed method, it is applied to the interface system using eye movement and is tested with a group of 25 users through playing a 'aligns games.' The results show that the system process more than 30 frames/sec on PC for the $320{\times}240$ size input image and supply a user-friendly and convenient access to a computer in real-time operation.

• Current Optics and Photonics
• /
• v.1 no.5
• /
• pp.538-543
• /
• 2017

Progressive addition lenses (PAL) have very wide application in the modern glasses market. The unique progressive surface can make a lens have progressive refractive power, which can meet the human eye's different needs for distance-vision and near-vision. According to the national glasses fabrication standard, the difference between actual optical power after fabrication and nominal design value should be less than 0.1D over the lens effective area. The optical power distribution of PAL is determined directly by the surface. Consequently, the surface processing accuracy requirement is proposed. Beginning from the surface expressions of progressive addition lenses, the relationship equations between the surface sag and optical power distribution are derived. They are demonstrated through tolerance analysis and test of an example progressive addition lens with addition of 2.09D (5.46D-7.55D). The example addition surface is fabricated under given accuracy by a single-point diamond ultra-precision machine. The optical power of the PAL example is tested with a focal-meter after fabrication. The optical power addition difference between test result and design nominal value is 0.09D, which is less than 0.1D. The derived relationship between the surface error and optical power is verified from the PAL example simulation and test result. It can provide theoretical tolerance analysis proof for the PAL surface fabricating process.

• Journal of Information Display
• /
• v.12 no.1
• /
• pp.37-41
• /
• 2011

Presented herein is a novel stereoscopic three-dimensional (3D) display system with active color filter glasses. This system provides full-color 3D images by applying the time-multiplexing technique on the original anaglyph method. By switching between the opposite anaglyph statuses, a full-color anaglyph is presented. A liquid crystal panel from a 3D monitor serves as an active color filter operating at 120 Hz. A display panel and a color filter are connected to one graphic card as a dual-link system, for synchronization. To test the quality of this system, a left/right-eye image separation test and an experiment with stereoscopic images were carried out. Although there was some crosstalk and blur, the system, as expected, provided full-color 3D display. This system overcomes a monochromatic 3D image, which is the major weakness of the original anaglyph system.

• The Journal of the Convergence on Culture Technology
• /
• v.7 no.1
• /
• pp.170-174
• /
• 2021

The purpose of this study is descriptive survey to quality of life by dry eyes experience in university students. The Korean version of the National eye institute visual functioning questionnaire (NEI-VFQ) was used to evaluate the quality of life. As a result of the study, 18.4% of the participants were diagnosed with dry eyes, and 63.2% experienced subjective dry eyes experience. The findings showed that the factors influencing the visual quality of life was wearing glasses, and the explanatory power for this 13.6%. Further research is needed considering the length of wearing glasses, contact lenses and severity of dry eyes.

• Journal of Korean Ophthalmic Optics Society
• /
• v.14 no.2
• /
• pp.53-59
• /
• 2009

Purpose: The aims of this study are to conduct a fact-finding survey of eyeglasses use based on the visual acuity of middle and high school students in Busan. Methods: A total of 821 middle and high school students from four different schools participated by Self-administered qustionnaire test on July, 2007. Results: Among these students, 74.3% of the students had low vision and 66.26% of the students wore eyeglasses. The percentage of non glasses-wearers were 13.77% in low vision and 15.26% of the students had low vision in glasses-wearers. The reason why they did not wear eye glasses and why they did not change eyeglasses prescription was they did not feel any inconvenience in their usual life. Conclusions: Many students have bad eyesight due to limited spheres of environment and they do not feel any inconvenience of non-wearing eyeglasses in spire of their bad eyesight.

• Journal of Korean Ophthalmic Optics Society
• /
• v.14 no.4
• /
• pp.1-10
• /
• 2009

Purpose: Recently because goggle and sunglasses is industrial products, unprofessional is selling in store what is not optical store. Due to layman's sale, check of frames or lens, the quality, curve, A/S, is impossible. Therefore layman's sale threated national eye-health. So we investigated in order to know them, merchant of goggle and sunglasses except for optician, about "how many they have optical knowledge?" and "What can they give a service us?" Methods: Regardless age, we get a survey of 208 person who purchased goggle and sunglasses in a store that it is not optical store and 100 of goggle and sunglasses except for optician. Results: Most merchant who haven it knowledge about glasses sells goggle or sunglasses. Even though merchant has knowledge about glasses, It was very littles, now. Conclusions: Optician who have expert knowledge need method that it was very littles. So goggle and sunglasses that it is registered industrial products need method to transform into health instrument.

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