Incidence of visual fatigue among students wactching natural-light TV and common LCD TV

Objective To compare the incidence of visual fatigue between the students wactching natural-light TV and common liquid crystal display(LCD)TV.Methods Fifty-nine colleges tudents with normal vision were recruited.Every subject was asked to watch natrual-light TV and common LCD TV,respectively.Then the visuognosis persistence,flicker fusion crtical frequency,attention span,visual reaction time,brightness difference threshold,dose work test,and subjective symptoms were measured before and after watching TV.Results The differences in value of attention span,visual reaction time,brightness difference threshold before and after watching TV were smal.lThe differences in values of visuognos is persistence,flicker fusion crtical frequency was greater in natural-light TV group than that of in common LCD TV group but without significance(P>0.05).The incidence of subjective symptoms increased after watching natural-light TV,but more subjective symptoms occured after watching common LCD TV(P<0.05).Conclusion Compared to watching common LCD TV,natural-light TV may ease the visual fatigue,but further studies should be made to confirm the effectubjective symptoms are minor after watching natural-light TV than watching common LCD TV.