wellness
Iranian Researchers Link Late-Night Phone Use to Shorter Sleep Duration
Iranian researchers link late-night device habits to shorter sleep among Tehran adults amid rising smartphone penetration.
How we reported this
A University of Tehran study released this month found that residents who used screens within one hour of bedtime slept 47 minutes less on average than those who avoided them.
The finding arrives as mobile subscriptions in the capital exceed 22 million and many professionals extend work into the evening on laptops and phones. Evening screen exposure matters now because Tehran’s traffic patterns and long commutes already compress available rest hours for workers in districts such as Vanak and Niavaran.
Local programs tracking device habits
Tehran Municipality’s District 3 health office began offering free workshops last October at the Enghelab Cultural Center on how to set device curfews. Participants receive printed guides showing recommended screen cut-off times and can join follow-up sessions held every Tuesday evening. Across town, the Sleep Disorders Clinic at Imam Khomeini Hospital runs a parallel pilot that logs patient phone data for two weeks before recommending adjustments; the clinic has enrolled 180 adults since the program started in March 2025.
The University of Tehran research team examined 1,240 adults aged 25 to 55 living inside the city’s ring road. Volunteers kept sleep diaries and wore wrist monitors for seven nights. Those reporting more than two hours of screen time after 9 p.m. showed delayed melatonin onset by roughly 90 minutes and spent 12 percent more time awake during the night. The study controlled for caffeine intake and shift work, both common among taxi drivers and hospital staff in central Tehran.
Residents who want to test changes can start with simple steps already promoted by the District 3 workshops. Switching phones to night mode after 8 p.m. costs nothing and reduces blue-light output. Families in Elahieh have reported buying basic blue-light filter glasses at local pharmacies for 180,000 rials each. Turning off notifications on bedside tables remains the most cited tactic among clinic patients who regained 30 minutes of sleep within the first week of trials.