EMDR is not simply the use of eye movements. Rather it is a comprehensive therapeutic approach with principles, protocols and procedures with the goal of reducing distress in the shortest period of time.
When you first meet with your EMDR therapist, your therapist will spend time getting to know your history. This generally includes the kind of distress you are experiencing, the kind of diffulties have you experienced, if you have physical problems, if you are taking medication and explore the support you have. If your therapist feels EMDR is suited for your difficulty, then s/he will describe the EMDR model to you and explain the theory.
You can ask your therapist questions and express any concerns you may have. Your therapist will spend some time doing some relaxation exercises with you, which could include 'safe or pleasant place' exercises, guided visualisation, deep muscle relaxation, breathing retraining etc.
Once you and your therapist feel that you are sufficiently prepared, you can then target a distressing memory with the eye movements or other forms of left-right alternating stimulation, such as sound or taps. Your therapist will ask you to select an image that represents the distressing event. You will then be asked to think about negative and positive thoughts, your feelings, the amount of distress you feel and where you feel it in your body.
Your therapist will then begin the eye movements while you hold the image in mind. After each set of eye movements your therapist will ask you what came to mind or what you noticed during the eye movements. During the eye movements you may experience the distressing event quite intensely to start with, but this distress generally reduces as the memory is processed with EMDR.
Your therapist will continue with the eye movements until your distress is reduced as much as possible. Your therapist will then ask you to think about your positive thought and also check whether there is any part of your body where you still feel distress. Before the end of the session, your therapist will give you time to feel calm again, using the safe-pleasant place exercise or relaxation techniques.