One of the ways to treat a brain injury is by correcting disruptions to sleep and sleep cycles. In a study published in the journal Neurobiology of Disease, researchers found that blue light therapy may re-entrain the circadian rhythm and help in improving sleep problems of people with mild traumatic brain injury (mTBI). This can help in their overall recovery because sleep and sleep cycle are two very powerful means of improving cognitive health. 
For the study, the team selected from volunteers aged between 18 and 50 from the greater Boston Metropolitan area. These were people who were diagnosed with a concussion or non-complicated mTBI in the preceding 18 months up to 4 months prior to the study. Volunteers had to go through a telephone screening followed by a one-on-one interview before being selected. In all, 32 participants were selected.
The experimental group was exposed to 30-min pulses of blue light daily for six weeks, while the control group was exposed to amber placebo light. The group exposed to blue light reported improved sleep timings, executive functioning, and reduced daytime sleepiness. The team also observed increased thalamic volume and structural connectivity in the brain. These results show the association of improved sleep with trauma recovery.