How many studies support Dark Sleep Environment?

Research on night-time light exposure is supported by a large prospective cohort study linking light exposure at night to higher cardiovascular disease incidence, alongside a microlongitudinal study finding night-to-night associations between light exposure and sleep health, and broader reviews on artificial light at night and circadian disruption. That's backed by 6 published studies in Vitaebase's database, the most recent from 2025 -- a modest but real research base.