Hypnosis, also referred to as hypnotherapy or hypnotic suggestion, is a trance-like state in which you have heightened focus and concentration. ... When you're under hypnosis, you usually feel calm and relaxed, and are more open to suggestions. In hypnosis, there is often a reddening of the eyes. Though not observable outwardly, a person in trance often reports fogging or blurring of the vision. Hypnosis can also cause tunnel vision, or even changes in the colors, sizes, and shapes of things. A person in hypnosis will be less distracted by outside sounds.