Table 5. The association of illuminance on subjective variables (alertness, safety, preference, visual comfort, satisfaction and performance).

	Illuminance (lux)
	<300	300-500	>500	p.v
Alertness	3.5(1.4)	3.1(1.1)	3.3(0.8)	0.43
Safety	1.1(1.0)	1.1(1.0)	1.2(0.9)	0.94
Preference	9.3(3.0)	7.9(2.5)	7.3(1.8)	0.01
Visual comfort	8.8(3.5)	10.3(3.4)	9.9(3.2)	0.17
Satisfaction	1.8(0.9)	2.4(0.5)	2.2(0.6)	0.02
Performance	2.7(1.0)	2.7(0.8)	2.6(0.9)	0.98