Table 1

Background of subjects

Dark condition
(n=17)
Well-lit condition
(n=10)
SexMale01
Female179
AgeMean±SD34.6±13.236.0±13.1
Mean duration of workMean±SD12.4±13.613.6±13.4
Sleep disorderNo117
No answer63
Sleeping drugNo127
No answer53
Past illnessAllergy10
Asthma11
Myoma of the uterus10
Fatty liver01
Slipped disk10
Corrected eyesightLeft0.94±0.270.76±0.43
Right0.92±0.320.81±0.63