Your speaking is not marked on eye contact or any physical gestures you make throughout your interview. However, it would be a good idea to look at your examiner in the eye because not only is it polite to do so, but it would certainly help in building your confidence, especially if you see your examiner smiling at you.
You will not get a high score if you lose your fluency and coherence, keep making grammar, vocabulary and pronunciation errors. But certainly not if you do not look at the examiner!