Table 1.

Delay in the melatonin rhythm following 1, 2, or 3 hours of light exposure

Duration of Light (hours)	N	DLMO 50% (hours ± SD)**	DLMOff 50% (hours ± SD)
1	18	−0.17 ± 1.06	−0.37 ± 0.92
2	22	−0.88 ± 1.05	−0.45 ± 0.85
3	16	−1.46 ± 1.67	−0.94 ± 1.41

^**P = 0.01