Lab tests found Apple Watch and Fitbit sleep timing can miss clinical sleep by over an hour, the article reports.

Researchers compared consumer wearables carefully against traditional polysomnography sleep labs.

Device algorithms often miscalculate REM and deep-sleep phases during the night.

Trackers may treat stillness as sleep even when the brain is still awake.

A Pittsburgh neuroscientist warned sleep scores can fuel bedtime anxiety.

Clinical labs rely on brainwave monitoring, not just movement sensors.

Experts say trendy hacks like mouth taping can hide sleep apnea risks.

Health authorities urge users to treat wearable data as guidance, not diagnosis.

Read the full article for more details on wearable sleep accuracy gaps.