The Impact Of Display Light Exposure On The Related Symptoms Of Eyesight And The Responses Of Visual Function And The Dynamic Changes Of Serum Lutein To Lutein Supplements In People With Long-term Display Light Exposure

Objectives: To realize the current situation of eyesight related symptoms and analyze the influential factors. To find out the impact of display light exposure on college students'eyesight symptoms.To examine the effect of different doses of lutein supplementation on visual function and trend of dynamic change in level of serum lutein in people with long-term display light exposure.Subjects and methods: A questionnaire Survey of 2 222 undergraduate and graduate students from four key universities in Beijing was carried out to analyze the influential factors and to find out their exposure time to display light exposure and their eye symptoms. The relationship between display light exposure of students in different grades and universities and their eye and general symptoms were analyzed and compared. 37 persons with long-term display light exposure were randomized in a double-blind study involving supplementation with 6 mg lutein/d, 12 mg lutein/d, or placebo for 12 weeks. Levels of serum lutein were measured in 0 wk,1 wk,3 wk,6 wk,9 wk,12 wk and 18 wk.Visual function indexes such as visual acuity (VA), contrast sensitivity (CSF), and glare sensitivity (GS),break-up time (BUT), critical flicker fusion frequency (CFF), visuognosis persistence, and reaction time were measured at week 0 and 12 throughout the study.Results: In all students, the occurrence rate of eyesight related symptoms was 66.0%. The affecting factors were daily computer usage, mental status, myopia, mental stress, air quality, noise, vegetable intake, familial eye disease. The mean display light exposure time of students in the four universities was (5.20±3.06)h/d and the mean exposure time tends to increase along with the rise of grade. The longer the exposure time was, the more apparent the eye became. The symptoms with the highest prevalence are eyesight decline, blurring of vision, dryness of eye.After lutein supplements, No statistically relevant changes from baseline were observed in uncorrected visual acuity and best-spectacle corrected visual acuity, and there was a trend toward increase in visual acuity in high-dose group. Contrast sensitivity and glare sensitivity in high-dose group increased with supplementation, although statistical significance was reached only in contrast sensitivity; Contrast sensitivity slightly improved in low-dose group, and statistically significant differences were only found at visual angles 2.5 degree. In addition, no significant side effects or changes were observed in any of the subjects during the study. there was a significant increase of break-up time in left eyes of subjects of high-dose group; Visuognosis persistence significantly improved, and significant change of simple reaction time was observed in high-dose group during the study. No statistically relevant change from baseline was observed in critical flicker fusion frequency, discriminative reaction time and choice reaction time.Conclusions: Students in higher learning colleges showed higher rate of eyesight related symptoms, the current situation of eyesight symptoms was related to the use of the eyes, individual health condition, psychological status, environment and dietary status, etc.Long time exposure to PC screens is harmful to eye and general health, and health education towards college students should be strengthened in order to prevent the damage on health by display light exposure.Visual function indexes such as contrast sensitivity, break-up time, visuognosis persistence and simple reaction time in people with long-term display light exposure who received the lutein supplements significantly improved,suggesting that a higher intake of lutein, may have beneficial effects on the visual performance of people.