Sleepless nights have been a way of life for Lisa Smith for nearly three decades.
>> I can sleep for a good 15 minutes, go into a deep good 15 minute sleep, and all of the sudden, I'll be wide awake.
>> She's convinced her tossing and turning started when her tour of duty ended, but her body's military time clock didn't.
>> So I'm still getting up early in the morning, 4:30, 5 o'clock to get ready, as if I'm getting ready to be standing in the 6 o'clock formation.
>> She also began developing back pain.
Now, a new study is shedding light on why.
>> We live on a planet that has a 24 hour day, so because of that plants, animals, fish, lizards, everybody has some sort of circadian rhythm tied to that 24 hour clock.
>> Your body clock, officially known as your circadian rhythm helps control the release of melatonin essential for a good nights rest.
Researcher John Burns says when your body is out of sync.
>> What accompanies that is sleep disorder, sleep problems and mood problems, and we also think increases in pain sensitivity.
>> Now reaserchers at Rush University are testing a drug free alternative to treatment, light therapy.
Aftr they wake up, participants like Lisa, sit in front of a UV free light box for an hour to help reset their bodies clock.
>> It just feels like a bright day.
>> And it works.
>> It reminds me of when I was a kid.
In the summer time, I would play outside under the sun for so long, and then at night time, I was just wore out, it was time to go to bed.
>> For the first time in years, she's sleeping soundly and waking up without pain.
I'm Martie Salt, reporting.