Mechanism of action of tasimelteon in non-24 sleep-wake syndrome: treatment for a circadian rhythm disorder in blind patients.

ISSUE: Many individuals with total blindness can develop a circadian rhythm disorder-called non-24 sleep wake syndrome-because they cannot detect light to resynchronize their sleep-wake cycles. A new melatonin 1 and melatonin 2 agonist tasimelteon improves sleep in these patients, resetting their circadian sleep-wake clocks.