EMDR stands for Eye Movement Desensitization and Reprocessing. It involves a therapist directing a patient's eye movements while recalling a traumatic memory to make the memory less distressing. The machine that produces light for the patient's eyes to follow was invented to help standardize the eye movements in EMDR therapy. EMDR is effective at processing emotional memories, which are painful due to being stuck in an unresolved state associated with the initial trauma.