EMDR is Eye Movement Desensitization and Reprocessing (EMDR), a psychological technique sometimes used in the treatment of post-traumatic Stress Disorder (PTSD).
EMDR is sometimes used to treat PTSD patients by asking them to focus on traumatic memories while moving their eyes from side to side following the therapist's finger or some object. Ssometimes headphones with alternating sounds from left to right ear are used. It is hypothesized that the switching from left brain to right brain establishes connections which allow the patient to access locked memories and emotions.
EMDR is a controversial treatment and has not been scientifically validated in clinical trials. You can find more info on EMDR at http://www.emdr.com.