AIM: To investigate the effect of blocking short wave visible light(400-500nm)on tear film stability in healthy people.

METHODS: In this prospective intervention experiment, 26 college students were selected, including 12 males and 14 females, aged 22.1±1.4 years, from February to March 2020. At the same time of two adjacent days, the subjects watched the video for 1h under the same environmental conditions. For the first time, there was no short wave visible light blocking, and for the second time, they wore short wave visible light blocking myopia or flat glasses. The subjects were examined the radius of curvature of lacrimal River curved surface, tear osmolality, tear film rupture time, corneal fluorescein sodium staining score, the basic state before watching the video and after watching the video respectively. And the questionnaire of visual perception was completed at the end of the experiment.

RESULTS: There were significant differences in the radius of curvature of lacrimal River curved surface, tear osmolality, tear film rupture time, corneal fluorescein sodium staining score between the basic state and the short wave visible unstopped state(t=4.50, 5.72, 4.437, 3.245, P<0.05). There was no significant difference between the short wave visible light blocking and the basic state(t=1.972, 1.993, 1.921, 1.641, P>0.05). There was also significant difference between the short wave visible light blocking and the short wave visible light unblocking(t=2.825, 3.771, 2.610, 3.028, P< 0.05). The results of the questionnaire showed that: eighteen subjects(69%)said that wearing the short wave visible light blocking glasses or without wearing short wave visible light blocking glasses had slight eye dryness, pain, foreign body sensation, visual fatigue and other discomfort after watching the video. Sixteen subjects(62%)said that they were more comfortable after blocking the short wave visible light. Twenty-four subjects(92%)said that they were willing to block the short wave visible light.

CONCLUSION: The stability of tear film could be reduced by watching the display screen for a short time. Blocking the short wave visible light could protect the stability of tear film of the ocular surface.