A research that the United States military sponsored suggests that blue light can help heal mild traumatic brain injury simply by making the person sleep better.

Mild traumatic brain accident (mTBI), or concussion, may result from a variety of causes, from a car accident to fights, falls or sports.
After such an incident, people may see stars, become disoriented, or even temporarily lose consciousness, but many come round without realizing they’ve been caught.
For some, however, mTBI may lead to symptoms for weeks or months, including headaches, mental fogginess, dizziness, loss of memory, fatigue, and disturbed sleep. Around 50 per cent of people with mTBI complain of persistent sleep problems after the injury, which affects their ability to function and heal, according to the researchers behind the current study.
Around 15 per cent of mTBI patients have symptoms that last for at least one year.
Scientists believe these effects are due to the stretches and tears inflicted on microscopic brain cells by impact.
“The brain is like the thick Jell-O consistency,” the lead author William D explains. “Scott” Killgore, a professor of psychiatry at the University of Tucson, Arizona. “Imagine a Jell-O bowl getting hit from a punch or slamming in a car accident against the steering wheel. What’s it up to? The shock is absorbed as it bounces around. Microscopic brain cells thinner than a strand of hair can easily stretch and tear and break out of force during the impact.”
Such injury can also occur during explosive blasts, when shock waves hitting the gut’s soft tissue push a surge in the brain, damaging the blood vessels and brain tissue.
“Mild traumatic brain injury (mTBI), commonly known as concussion, is one of military personnel’s most common injuries and is a major global health concern,” Killgore told NCCMED.
Sleep like a healer
“There are almost no effective concussion treatments today,” Killgore said. “We’ve been searching for a nonpharmacological (or nondrug) approach to help people.”
Killgore and his research team earned US funding. Army Medical Research and Development Command to perform the research appearing in the journal Disease Neurobiology.
Sleep was the solution which they set out to prove successful.
“Since sleep is so critical to brain health and recovery, we hypothesized that improving the timing and duration of sleep could lead to faster recovery from mTBI,” Killgore said. “Notable evidence suggests that sleep is important for processes of brain repair,” he said.
Killgore clarified that scientists have shown that sleep stimulates the production of new insulating brain cells, called oligodendrocytes, following an injury.
“Without enough restorative sleep, brain tissue regeneration will possibly be slowed down or incomplete,” Killgore said.
Blue light in the morning
The recent clinical trial, involving 32 adults with mTBI, focused on strengthening the circadian rhythm of the participants– the natural process that dictates our 24-hour sleep-wake cycle.
This was accomplished by the researchers exposing the participants for 6 weeks each morning to blue light from a cube-like system for 30 minutes early. At the control group participants used amber lights instead of blue.
Scientists have shown that blue light suppresses melatonin production in the brain, a chemical which makes us sleepy.
“Blue light is a key timekeeper in the brain,” Killgore explained. “The exposure to blue light, such as sunlight at dawn, informs the body that stopping sleep is morning and time. That makes you more alert during the day and begins the ticking of the clock to tell you when to go to sleep later.”
By using blue light, the participants reset the inner clock of the brain, allowing the participants to sleep early and sleep longer. The most restorative, and therefore efficient, sleep occurs when it is in sync with the inherent circadian rhythm of the body.
Participants who used the blue light therapy fell asleep on average and woke up 1 hour earlier than before the trial and were less drowsy during the day. Our brain-processing speed and efficiency have been improved, and the visual emphasis has been increased.
“Our findings suggest that exposure to morning blue light helps to reset the normal sleep-wake cycle every day, improving the ability to sleep better at night, leading to better recovery from concussion
William D. “Scott” Killgore
The explanation blue light gets a bad rap from phones, machines, and televisions is timing. Night-time blue light will trick your brain into thinking it’s morning, so messing with sleep.
Scientists are also investigating the effect of blue light on the sleep of those with mental disorders, such as post-traumatic stress disorder, as well as the ability of blue light to improve healthy people’s alertness.