EMDR, or eye movement desensitization and reprocessing therapy, was initially developed by Francine Shapiro to treat PTSD. The method uses bilateral stimulation (visual tracking, auditory or tactile stimulation) while the patient focuses on traumatic or disturbing memories. They also focus on the cognition and emotions that accompany the memories. When the memories are desensitized, the patient then reprocesses using positive cognitions.
EMDR has been controversial in part because when it was developed there were a fair number of zealous adherents who hailed it as a miraculous cure before there was much evidence for it. Over the years, however, some well-designed studies have shown that it is genuinely efficacious in the treatment of PTSD. In particular, studies have demonstrated its superiority to exposure therapy alone. This had been a criticism of EMDR — that it was essentially just an exposure therapy and that the eye movements were superfluous.