It means that you are responding to the Hemi-Sync process. However, if you are experiencing a great degree of discomfort, you may have the volume too loud. For best results, the volume should be just loud enough for you to hear the verbal instructions. This is a phenomenon common to the shift in energy levels such as the shift from Consciousness 1 to Focus 10. Consult your physician.
Some people report seeing light, color, and form, but others quite frequently perceive sensations.
Some people hear a rushing sound, buzzing, voices, verbal messages, or even music. Just relax and observe your own perceptions without judging how you should feel. The perception of light suggests that your potential for nonphysical awareness is developing but it is up to you to decide on its meaning. Such light is widely reported by explores of higher consciousness and people who have had near-death experiences. It is often accompanied by euphoria, a feeling of oneness with the universe, and a sense of overwhelming love.