Normal values for sleep

A sleep study of over 50,000 women showed night-time artificial light and air pollution were associated with shorter sleep duration. Living in green space areas led to longer sleep duration. Unsurprisingly, environmental noise caused delay in falling asleep. In another study, females averaged 8.3 hours sleep per night at age six, falling to seven hours for young adults, increasing slightly at age 65. Males needed

8.1 hours per night at age six, falling to 6.5 hours in early adulthood, increasing slightly after 60.