Table 1.

Effects of filtering visual short wavelengths (<480 nm) on nighttime sleep structure variables.

Sleep variable	Comparator (C) Mean ± SEM	Baseline (B) Mean ± SEM	Intervention (I) Mean ± SEM	p	C vs. B	C vs. I
Total sleep time (min)	476.67 ± 17.32	397.67 ± 18.67	437.78 ± 14.37	0.0107	0.0067	0.2375
Sleep efficiency (%)	91.42 ± 1.40	78.14 ± 4.01	85.94 ± 3.32	0.0221	0.0142	0.5763
Stage 1 (min)	29.00 ± 7.97	22.67 ± 3.92	20.39 ± 2.50	0.5416
Stage 2 (min)	231.08 ± 9.87	217.28 ± 15.17	238.56 ± 7.53	0.2371
Stage 3 (min)	18.58 ± 1.42	19.83 ± 2.53	22.06 ± 2.60	0.6210
Stage 4 (min)	77.83 ± 10.37	51.83 ± 5.11	63.31 ± 9.97	0.1667
REM (min)	120.17 ± 13.10	85.50 ± 9.17	92.67 ± 9.73	0.1168
NREM (S2 + S3 + S4) (min)	327.50 ± 12.64	288.94 ± 17.00	323.92 ± 12.09	0.0476	0.0771	0.9973
SWS (S3 + S4) (min)	96.42 ± 9.71	71.67 ± 5.46	85.37 ± 10.57	0.1982
Sleep onset latency (min)	13.27 ± 5.76	14.37 ± 2.33	10.59 ± 1.89	0.6643
REM onset latency (min)	59.25 ± 11.21	103.28 ± 20.78	72.00 ± 4.05	0.0907
WASO (min)	22.42 ± 5.80	73.00 ± 21.43	37.39 ± 17.64	0.0237	0.0338	0.9147

Data represent mean ± SEM. Data were subjected to repeated-measures one-factor (Group) mixed-model ANOVA. If a significant main effect was observed, the analysis was followed by Dunnett’s multiple-comparison tests to assess differences between intervention and baseline groups relative to the comparator group.