Hi Saratoga Yogi,
I would agree with Shanti, it is a phase in meditation, and there is nothing wrong. Things come up during meditation, lights, sounds visions, dream like states, emptiness, it is all just stuff of the mind. We simply favour the mantra and carry on. If you open your eyes, or change your mantra deliberately to try and get rid of something that is happening, then you are reacting to a mind state rather than following the meditation procedure. It is actually a good sign, as it shows that your mind is relaxing enough to access stuff which is normally subconscious and only accessible to the mind during sleep.