Here is some interesting advice:
Morning light seemed to be particularly powerful: those exposed to a high stimulus between 8:00 and 12:00 took an average 18 minutes to fall asleep at night, compared to 45 minutes in the low stimulus group. They slept for an extra 20 minutes. Their sleep efficiency was 2.8% higher. And they reported significantly fewer sleep disturbances. These associations were stronger during winter, when people may have had less opportunity to receive natural light during their journey to work.
Gordijn also recently published a study which found that people slept better following more exposure to daylight. Here, the participants were wired up to polysomnography monitors to record their sleep in detail. “People had more deep sleep, and it was less fragmented after more exposure to daylight,” Gordijn says.