EMDR is "eye movement desensitization .....im not sure what the R stands for.............
Eye Movement Desensitization and Reprocessing
The theory is that bilateral stimulation (achieved by following the "bouncing ball" from left to right with the eyes only) somehow accesses the memory portion of the brain including the emotional components of the memory, allowing them to be processed in a healing way instead of being stored as a traumatic memory that affects the entire being. The bilateral stimulation can be accomplished visually, audibly, and through the use of alternately buzzing pods held in the hands or on the thigh.
It's been accredited by many major mental health organizations world-wide, and is recognized as a primary treatment for PTSD by the American Psychological Association.
The long and the short of it is, it works fast and well for most people, often times without "reliving" the memories as they are processed.