• Journal of Preventive Medicine and Public Health
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• v.25 no.3 s.39
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• pp.247-268
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• 1992

This study was conducted to evaluate the effect of VDT work on eyes and vision among workers in a TV manufacturing plant. The study subjects consisted of 264 screen workers and 74 non-screen workers who were less than 40 years old male and had no history of opthalmic diseases such as corneal opacities, trauma, keratitis, etc and whose visual acuity on pre-employment health examination by Han's test chart was 1.0 or above. The screen workers were divided into two groups by actual time for screen work in a day : Group I, 60 workers, lesser than 4 hours a day and group II, 204 workers, more than 4 hours a day. From July to October 1992 a questionnaire was administered to all the study subjects for the general charateristics and subjective eye symptoms after which the opthalmologic tests such as visual acuity, spherical equivalent, lacrimal function, ocular pressure, slit lamp test, fundoscopy were conducted by one opthalmologist. The proportion of workers whose present visual acuity was decreased more than 0.15 in comparison with that on the pre-employment health examination by Han's test chart was 20.6% in Group II. 15.0% in Group I and 14.9% in non-screen workers. However, the differences in proportion were not statistically significant. The proportion of workers with decreased visual acuity was not associated with the age, working duration, use of magnifying glass and type of shift work (independent variables) in all of the three groups. However, screen workers working under poor illumination had a higher proportion of persons with decreased visual acuity than those working under adequate illumination (P<0.05) . The proportion of workers whose near vision was decreased was 27.5% in Group II, 18.3% in Group I, and 28.4% in non-screen workers and these differences in proportion were not statistically significant. Changes of near vision were not associated with 4 independent variables in all of the three groups. Six out of seven subjective eye symptoms except tearing were more common in Group I than in non-screen workers and more common in Group II than in Group I (P<0.01). Mean of the total scores for seven subjective symptoms of each worker(2 points for always, 1 point for sometimes, 0 point for never) was not significantly different between workers with decreased visual acuity and workers with no vision change. However, mean of the total scores for Group II was higher than those for the Group I and non-screen workers (P<0.01). Total eye symptom scores were significantly correlated with the grade of screen work, use of magnifying glass, and type of shift work. There was no independent variable which was correlated with the difference in visual acuity between the pre-employment health examination and the present state, the difference between far and near visions, lacrimal function, ocular pressure, and spherical equivalent. Multiple linear regression analysis for the subjective eye symptom scores revealed a positive linear relationship with actual time for screen work and shift work(P<0.01). In this study it was not observed that the VDT work decreased visual acuity but it induces subjective eye symptoms such as eye fatigue, blurred vision, ocular discomfort, etc. Maintenance of adequate illumination in the work place and control of excessive VDT work are recommended to prevent such eye symptoms.

• Korean Journal of Occupational Health Nursing
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• v.6 no.1
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• pp.5-13
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• 1997

For the purpose of investigating the subjective symptom of industrial fatigue, a questionnaire survey was carried out on 282 labor workers and 189 managerial workers who were employed at the manufacture of electronic products in two small scale industries. Checklist of industrial fatigue was composed of physical symptoms(10 items), mental symptoms(10 items), and sensory neurotic symptoms(10 items). The results were as follows : 1. Complain rate of fatigue was the highest in "eye strain" of physical symptom, "feel anxious about things" of mental symptom, and "feel stiffness in the neck or the shoulders" of sensory neurotic symptom in labor workers and managerial workers. 2. Managerial workers demonstrated II dominant type (mental or night work type), while labor workers demonstrated I dominant type of fatigue (general type). 3. Mean weighted score of fatigue complaints in labor workers (23.16) was significantly higher than that in managerial workers (20.34). 4. Mean weighted scores of fatigue complaints in male, 5~9 years of work duration, married, 4~5 hours of sleeping time, graduation of high school and college, and large of workload were significantly higher in labor workers than in managerial workers. 5. In poor work condition with temperature, ventilation, illumination and noise, the average weighted score was significantly higher in labor workers than in managerial workers.

• Korean Journal of Occupational Health Nursing
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• v.16 no.1
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• pp.37-47
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• 2007

Purpose: To find out the relationship between the shift work, and disrupted sleep and consequent fatigue symptoms. Methods: The questionnaires were given to 345 nurses of 4 hospitals with over 400 beds in Daejeon. Results: The shift workers showed worse subjective quality of sleep than the daytime workers, and had significantly higher frequency of "cannot get to sleep within 30 minutes", "wake up in the middle of the night" and "wake up in the early morning". The shift workers had significantly higher scores of subjective symptoms of fatigue than the daytime workers, and the fatigue was found to be the mental type. The subjective symptoms of fatigue scores were significantly higher in the group who had "cannot get to sleep within 30 minutes", "wake up in the middle of the night" and "wake up in the early morning". Conclusion: The study results indicated that the shift workers had the higher level of subjective symptoms of physical fatigue as well as the worse quality of sleep than the daytime workers. It is speculated that the factors attributable to the poor quality of sleep or sleep induction disorders of nurses of hospitals could be due in major part to adaptational difficulties resulting from frequent night shifts.

• Physical Therapy Korea
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• v.7 no.1
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• pp.79-90
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• 2000

Participants of this 1998 survey included 100 physical therapists working in hospitals located in Andong City. 77.7% of the participants were in their twenties and 20.2% in their forties. 46.4% of the participants were 3rd year students at a junior college, and 1.0% were college graduates. 67.6% of the participants had less than 5 years experience and 1.0% 16 years experience in their field. 59.6% of the participants were married. Regarding questions about occupational satisfaction, many of the participants replied "normal" for the first and third questions, and few answered "very much". Most of the participants answered "normal" for all the questions concerning their work environment with few replying "very much". With regards to awareness of the physical signs of fatigue, "occasionally, yes" were the most frequent answers. Regarding awareness of the psychological signs of fatigue, the similar proportions of participants answered "occasionally, yes" as that for "feeling nothing". Similarly, with regard to awareness of the neuro-sensitive signs of fatigue, there was a similar ratio of participants answering "occasionally, yes" and "feel nothing". It can be concluded that there are many causes of fatigue amongst physical therapists. Improvements in daily nutrition, mental health and general well-being are important in tackling these problems. It appears that fatigue amongst physical therapists may be cumulative and due to prolonged working hours To promote better daily functioning and early recovery from fatigue, appropriate assignments of working and resting hours are necessary. They would also benefit the prevention of symptomatic problems in the waist and shoulder.

• Journal of Preventive Medicine and Public Health
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• v.24 no.3 s.35
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• pp.305-313
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• 1991

In order to investigate industrial fatigue due to visual display terminal (VDT) work of banking operations the questionnaire survey for subjective symptoms of fatigue was carried out on 470 bank clerks who had been engaged in VDT work for various length of work hours. The questionnaires comprised three groups of 10 items each, representing dullness and sleepiness (level of cerebral activation), difficulty in concentration (level of motivation) and bodily projection of fatigue. The results were as follows : 1. Of the 30 items of questionnaires, the highest percentage was accounted for by 'eye strain' (51.5% ), followed by 'feel stiffness in the neck or the shoulders'(33.4%), 'feel a pain in the low back'(26.8%), 'whole body feels tired'(19.6%) and 'feel headache'(17.9%) in the order of sequence. 2. The average weighted score for the first group of questionnaire items (dullness and sleepiness) was the largest among three groups and was followed by 'the third cup (bodily projection of fatigue) and the second item group (difficulty in concentration) in the order of sequence, suggesting the heavier mental stress of VDT work in banking operations rather than physical burden. 3. In terms of the age and sex of workers, work duration and VDT work percentage, the difference in average weighted score was noted only between sex, the score of female being larger than that of male. 4. The complaint rates of subjective symptoms showed close associations with the subjective optimums of room temperature, ventilation, illumination and noise level. 5. The significant correlation was showed between age, work duration and item of 'whole body feels tired', between VDT work percentage and items of 'eye strain' and 'feel stiffness in the neck or shoulders' and between all items of subjective symptoms.

• Journal of the Korean Society of School Health
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• v.10 no.2
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• pp.169-178
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• 1997

In order to investigate the complaint rates of subjective fatigue symptoms and study the relationship between them and body type, health awareness in middle school students, we carried out a survey of 1,209 students (654 boy students and 555 girl students) at a middle school in Taejon City by a self-recorded questionnaire. The survey was conducted in June, 1997. The results obtained were as follows: 1. Among complaints of fatigue, "feel like lying down" was the highest, followed by "feel anxious about things", "feel drowsy", "yawning a lot", "eye strain" and "whole body feels tired" in descending order. 2. In the average weighted score of fatigue complaint, dullness and sleepiness (I) was the highest, followed by a difficulty in concentration (II) and bodily projection of fatigue (III) in descending order. Fatigue seems to create mental stress rather than physical burdens. 3. In the classification of body type based on the $R\ddot{o}hrer$ index, the obesity type (145 and above) was 11.0%, standard type (110~144) was 64.7% and leptosomic type (l09 and below) was 24.3%. Comparison between both sexes revealed that the rate of obesity and leptosomic types were significantly higher in boy students than in girl students. 4. In terms body type awareness, the statistics are the following: those who consider themselves to be standard type, 44.3%, slightly obese 24.5%, leptosomic, 23.5% and obese 7.8%. However, the level of obesity awareness was significantly higher in girl students than in boy students. 5. As for health awareness, 36.5% considered themselves healthy, 5.4% generally healthy and 10.1% a little unhealthy, but the level of unhealthy awareness was higher in girl students than in boy students. 6. In the relationship between body type and health awareness, most students thought that they were obese in spite of their standard body type. Also, many students who were obese and leptosomic tended to consider themselves to be a little unhealthy. 7. The more the students were obese or felt unhealthy, the more the average weighted score of fatigue complaints was high.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.4
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• pp.395-401
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• 2012

Purpose: The purpose of this study was to research any effect on vision protecting or decreasing VDT syndrome of extracted anthocyanine from fermented purple sweet potato and blueberry. Methods: Subjects were aged 19-20 years old who do not have ophthalmic and systemic diseases and over -N4.00 D of refraction error. 40 mg of extracted anthocyanine from fermented purple sweet potato, from blueberry, and control group, placebo were dosed at separate try. After 2 hours later, subjects were directed perform visual display terminal (VDT) work for 2 hours. Objective refractive error was measured before dosing anthocyanine and after VDT work for 2 hours. Degree of head ache, eye pain and strain and subjective symptoms of neck, shoulder and waist was also examined through interviews by dividing its degree into severe, moderate, slight or none. Results: After 2 hours VDT work, vision protection effect in terms of refractive error for dominant eye was decreased by $0.031{\pm}0.21$ D in the group of extracted anthocyanine from fermented purple sweet potato, $0.006{\pm}0.32$ D in the group of extracted anthocyanine from blueberry. However, there was significantly myopic progression in the placebo group by $0.144{\pm}0.28$ D (t=2.27, p=0.03). Conclusions: It is considered that extracted anthocyanine from fermented purple sweet potato inhibits increase of refraction anomalies of dominant eye rather than non-dominant eye after VDT work.

• Korean Journal of Occupational Health Nursing
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• v.7 no.2
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• pp.177-185
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• 1998

The purposes of this study were to investigate the effects of farming in greenhouses with respect to subjective fatigue symptoms among farmers and the degree of symptoms. The study compared 176 green-house farmers with 216 open field farmers using a subjective fatigue symptoms rating scale developed by the Industrial Research Institute of Fatigue, Japanese Association for industrial Hygiene. 1. With respect to complaint rates of the subjective fatigue symptoms, the results indicated that greenhouse farmers have, in order of severity, high degrees of low back pain, difficulty in collecting thoughts, and apt to forget. 2. With respect to cumulative scores of fatigue symptoms, the results indicated that both groups of farmers exhibited a lack of attentiveness and a high degree of dullness and sleepiness(category I), body projection of fatigue(category II), and difficulty in concentration(category III). 3. With respect to general characteristics, it was found that the degrees of subjective fatigue symptoms were found to be higher among females, people with lower educational levels, and the elderly, regardless of the group. 4. With respect to work related factors, farmers with more years of experiences were found to have higher degrees of subjective fatigue symptoms, except for open field farmers with less than nine years experience. Both groups of farmers were found to have high degrees of subjective fatigue symptoms when working less than eight hours a day and less than six months a year. 5. With respect to health habits, for people who get less than eight hours of sleep per day exhibited higher fatigue scores than people who get more than eight hours. People who do not smoke and drink also exhibited higher fatigue scores than people who smoke and drink. 6. The results of multiple regression showed that the risk factors related to the subjective fatigue symptoms of farmers in the greenhouse group were ages, levels of education, sex and for the comparison group, were sex. years of farming, and hours of sleep. The R-square were 12.5% in the greenhouse group and 12.1% in the comparison son group. The differences between the greenhouse and open field farmers in the degrees of fatigue symptoms were found not to be statistically significant even if the working conditions of the greenhouse farmers were poor. This may be attributed to non-work related factors, i.e., social, economical, and psychological factors among greenhouse farmers.

• Journal of Korean Public Health Nursing
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• v.7 no.1
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• pp.81-97
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• 1993

This study was carried out to analyze the factors of the perieved symptoms of fatigue of the industrial workers, to examine the inter-relatisnship of the above factors with their general charactenstics and the environments of working area for the examination of their health status and the effective health management of them. This study was undertaken from December 1 to December 20, 1990. The subjets were 495 workers who had worked at the Industrial complex located in Chonbuk Province. The result of this study were as follows: 1. The worker's percieved symptoms of fatigue were classified to the following seven factors; A) Musculo-Skeletal Symptoms, B) Neuro-Psychial Symptoms, C) Optical Symptoms, D) Heart Symptoms, E) Head Symptoms, F) Respiratory Symptoms, G) Genital Symptoms 2. Analysis of the inter-relationship of their percieved symptoms of fatigue with general characteristics; 1) The difference of distribution to their percieved symptoms of fatigue according to sexuality was significant; Female were higher than Male $(p{\leqq}0.001$, p<0.005) 2) The difference of distribution to their percieved symptoms of fatigue according to age was significant; Age group under 24 years of age were higher than the other's group (p<0.001). 3) The difference of distribution to their percieved symptoms of fatigue according to the level of education was significant; Workers who stand on a low intellectual were higher than workers on a high intellectual level. 4) The difference of distribution to their percieved symptoms of fatigue for a week was the highest when worked at sunday. 5) The difference of distribution to their percieved symptoms of fatigue for seasons was high at spring. 3. Analysis of the inter-relationship of their percieved symptoms of fatigue with the environments of working area. 1) The difference of distribution of their percieved symptoms of fatigue according to the working department was significant; Production workers were higher than office workers. 2) The difference of distribution of their percieved symptoms of fatigue related with working posture was significant; Sitting: Musculo-Skeletal symptoms (p<0.05), Optical symptoms (p<0.005) 3) The more dissatisfied with their's own duty they were, the higher became the distribution of their percieved symptoms of fatigue (p<0.001. p<0.005, p<0.05) 4) The more dissatisfied with their working condition they were, the higher became the degree of their percieved symptoms of fatigue (p<0.001. P<0.05) 5) The difference of distribution of their percieved symptoms of fatigue according to kinds of job was significant: Workers who has handled heavy materials were higher than who had not handled $(p{\leqq}0.001$, p<0.05). Workers who has handled chemical materials: Optical, symptoms $(p{\leqq}0.001)$. Workers who has handled dusty materials: Respiratory symptoms (p<0.01) 6) The environment of working area was significantly affected to the distribution of their percieved symptoms of fatigue: Workers complains of a illumination problem; Optical symptoms (p<0.005), Heart symptoms (p<0.005) Workers complains of a ventilation problem: Heart symptoms (p<0.05), Optical symptoms, Heart symptoms (p<0.01) Musculo-skeletal symptoms ($p{\leqq}0.001$)

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.1
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• pp.75-81
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• 2012

Purpose: The study tried to figure out accommodative changes by measuring accommodative response, appearing on the full vision correction and low vision correction, with both eyes open-view auto-refractometer (Nvision-K5001, Shin-nippon, Japan). Methods: It carried out objective and subjective refractions, targeting 79 college students (58 males and 21 females) aged between 20 and 30($21.14{\pm}2.00$), by measuring accommodative changes with fixation distance at 1.0 m for eyesight of 1.0 after full version correction. The distances of 5.0 m, 1.0 m, 0.50 m, 0.33 m and 0.25 m for eyesight of 0.8, 0.7 and 0.6 after low vision correction arbitrarily added plus lens were applied. Results: the shorter measure fixation distances were, the greater changes accommodative response showed a tendency in the state of both full vision correction and low vision correction(0.7). The state of full vision correction showed a greater change of accommodative response than that of low vision correction(0.7). Both right and left eyes showed low accommodative responses in the state of low vision correction(0.7) than that of full vision correction. As a result of analyzing accommodative response at an eyesight of 0.8, 0.7, and 0.6 after low vision correction, the poorer eyesight was the lower accommodative response. Conclusions: Low vision correction from a near distance is expected to avoid unnecessary accommodative response, make eyes relaxed and prevent accommodative function disorder.