Table 2.

Effects of filtering visual short wavelengths (<480 nm) on daytime 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	307.78 ± 33.16	341.52 ± 25.86	0.0006	0.0004	0.0025
Sleep efficiency (%)	91.42 ± 1.40	68.32 ± 7.07	75.36 ± 3.99	0.0098	0.0053	0.0414
Stage 1 (min)	29.00 ± 7.97	20.22 ± 2.74	24.09 ± 3.13	0.4280
Stage 2 (min)	231.08 ± 9.87	147.22 ± 17.60	155.94 ± 10.59	0.0026	0.0021	0.0047
Stage 3 (min)	18.58 ± 1.42	17.00 ± 2.76	13.94 ± 1.74	0.4702
Stage 4 (min)	77.83 ± 10.37	64.33 ± 9.75	75.72 ± 9.32	0.2980
REM (min)	120.17 ± 13.10	58.50 ± 11.86	71.22 ± 11.67	0.0025	0.0014	0.0083
NREM (S2 + S3 + S4) (min)	327.50 ± 12.64	228.56 ± 22.05	245.61 ± 16.46	0.0026	0.0016	0.0068
SWS (S3 + S4) (min)	96.42 ± 9.71	81.33 ± 10.11	89.67 ± 10.07	0.4624
Sleep onset latency (min)	13.27 ± 5.76	13.24 ± 4.16	4.76 ± 2.06	0.0673
REM onset latency (min)	59.25 ± 11.21	74.72 ± 9.90	76.89 ± 13.71	0.4565
WASO (min)	22.42 ± 5.80	88.72 ± 32.24	66.67 ± 22.10	0.0460	0.0269	0.1124

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.