Frequently Asked Questions

While morning sunlight doesn’t directly produce hormones, exposure to it does trigger your body to release and regulate key hormones:

Cortisol Morning sunlight signals your brain (through the eyes) to increase cortisol production. This helps wake you up, boost alertness, and regulate your circadian rhythm.

Serotonin Production depends less on light perception and more on overall brain chemistry and activity. So blindness itself doesn’t stop serotonin production, though the lack of light exposure may lower it somewhat in people with no light perception.

Sunlight exposure stimulates serotonin production in the brain, which improves mood and focus. Later in the evening, serotonin is converted into melatonin, the sleep hormone.

Vitamin D Blindness does not affect vitamin D production. The skin still makes it when exposed to UVB rays, regardless of vision.

Melatonin Bright morning light helps “reset” your internal clock by telling your body to stop making melatonin in the morning, so that it will produce it again at night for sleep.

Vitamin D Technically a hormone precursor. UVB rays from sunlight help your skin synthesize vitamin D, which functions more like a hormone than a vitamin in the body.

So, morning sunlight helps boost cortisol and serotonin, suppresses melatonin (to wake you up), and allows your body to make vitamin D.

Note: Some blind people still have IPRG cells in their eyes, which detect light even if they cannot see images. If those cells work, sunlight can still help regulate cortisol in the morning and melatonin at night.

Potential Management Approaches:

Melatonin Supplements Taking a small dose at the same time each evening can help shift the body’s clock and signal “nighttime.” Works best when timed very precisely (usually an hour or two before desired sleep).

Tasimelteon (Hetlioz®) A prescription drug that mimics melatonin and binds to melatonin receptors more strongly. Specifically FDA-approved for Non-24 in totally blind individuals.

A Strict Sleep Schedule Going to bed and waking up at the same times daily, even when tired, helps anchor the body’s rhythm. Paired with behavioral strategies (like avoiding naps, caffeine, or late-night stimulation).

Other Zeitgebers (“time cues”) Since light isn’t an option, other cues like meal timing, exercise, and social routines can help provide structure for the circadian system.