SAN DIEGO -- Virtual reality has been used for years to help treat people with various phobias and fears. Now, the technology is being used by therapists to treat post traumatic stress in military personnel before the disorder disrupts their lives and careers.

For Pfc. Joshua Frey, the war in Iraq is all too real.

"I'm just very blessed I got to come home and tell my story," Frey said.

The Marine Corps machine gunner has quite a story to tell. Last November, Frey and his team were attacked by insurgents as they cleared a house during the fight for Fallujah.

"That's when my friend Dickinson was hit three times in the head with 762 rounds," Frey said.

Frey ran inside to get his friend out. That's when he said he was hit.

"I went in there (and) came out the back. Half my scapula was (taken) out. I can't use my arm at all," Frey said.

Frey received a Purple Heart for his shattered arm, but the loss of his friend shattered his world.

"Dickinson didn't make it that day. That's what hurt worst because we were getting ready to come home," Frey said.

Frey is home now. He's coping with the pain of his injury, but like many veterans, the war hero's pain is more than skin deep.

"I haven't had a good night's sleep in a long time. With the medication, I still have nightmares (about) the memories of that day," Frey said.

Doctors at Naval Hospital are helping Marines like Frey deal with their post traumatic stress by facing the ugly memories head on.

Navy psychologist Dr. James Spira uses virtual reality to help Frey literally retrace his steps through Fallujah.

Through biofeedback and relaxation techniques, Frey learns to navigate the virtual war zone calmly.

"As their arousal goes (up), they learn to control that. Then I can add more elements until finally nothing phases them. Then the nightmares decrease and the daily thought intrusions decrease," Spira said.

The journey back has been long and painful.

"It's been a roller coaster. It's been real hard," Frey said.

Frey said the therapy has been worth it.

The virtual reality program at Naval Medical Center San Diego is part of a three-year study to evaluate the therapy for treatment of post traumatic stress disorder in military personnel.

Doctors are hoping virtual reality might also be useful in preventing post traumatic stress disorder.