Visual Comfort and Acute Alerting Effects of Diurnal Intermittent Bright Light

Figures & data

Fig. 1. Visualization of the three experimental lighting conditions and measurement protocol of one session. IL = intermittent light, BL = bright light, DL = dim light, Ass nr = assessment number.

Fig. 2. Floorplan of the laboratory.

Fig. 3. Normalized spectral power distribution of the bright (solid line) and dim (dotted line) light settings.

Table 1. Illuminance, CCT, Color fidelity index, α-opic EDI, and α-opic DER of the light settings (at the eye position).

Light setting	Dim light		Bright light
Illuminance (lux)	111		1069
CCT (K)	4067		3989
Color fidelity index (Rf)	84		82
	α-opic EDI (in lux)	α-opic DER	α-opic EDI (in lux)	α-opic DER
S-cone-opic	76	0.68	594	0.56
M-cone-opic	97	0.87	936	0.88
L-cone-opic	111	1.00	1062	0.99
Rhodopic	76	0.69	717	0.67
Melanopic	67	0.61	624	0.58

Table 2. Upper (ΔU) and lower (ΔL) equivalence bounds that were used in the equivalence test for the alertness-related parameters.

	SD	ΔU	ΔL
Vitality	0.95	−0.49	0.49
KSS	1.95	−1	1
MRT	73.35	−37.62	37.62
MRT10%slow	150.85	−77.36	77.36
MRT10%fast	63.9	−31.95	31.95
SDRT	29.85	−15.31	15.31
CVRT	5.55	−2.85	22.85
Mean SCL	0.30	−0.15	0.15

Fig. 4. Temporal trajectory of a) vitality, b) sleepiness, c) mean reaction time for PVT, d) standard deviation for the PVT, e) mean reaction time for the 10% slowest responses of the PVT, f) coefficient of variation for the PVT, g) mean reaction time for the 10% fastest responses of the PVT, and h) PVT motivation. The graphs are based on the models without the correction for time in session. The error bars represent SE.

Fig. 5. Temporal trajectory of a) mean SCL, b) calm, c) happy, d) sensation of light intensity, e) sensation of color temperature, f) visual acceptance (in % – no statistical testing), and g) visual comfort. The graphs are based on the models without the correction for time in session. The error bars represent SE.

Data availability statement

The coded collected data is available to the general public in an online data repository (10.17605/OSF.IO/BSA9N).