From the Zen tradition, I learned to meditate leaving my eyes cracked open a little. Most other practices seem to be done with closed eyes. The Zen approach makes sense when you understand meditation as a practice in being fully present.
With eyes closed to outside stimulation, it is easier to sink into an altered state, whether becoming identified with the Divine within or with the various thoughts, daydreams and fantasies that will arise. With eyes open, I am more focused on my present surroundings, thus less able to attend to what is inside. Having the eyes slit open is as if they are both open and closed. I can focus on what is inside yet remain linked to the outside world where I sit.
The inner world includes the ordinary mind, the filters of experiences, expectations, fears, longings and mental chatter. Observing it during meditation helps me become conscious of what projections I have that interfere with true perception. Yet as the small, egoistic mind quiets down, something else becomes evident, an inner knowing that in Buddhism is called Big Mind or Buddha Nature. In Unity, we may call it the Divine or Spirit or God or the indwelling Christ.
Meditation makes me more conscious of how we are both human and divine. Adding prayer as a complimentary, more active approach, has allowed me to connect more to the Divine in my life. I notice more of the good in the world. I feel much better about life despite the many trying and at times scary events and issues that arise. Recognizing God as good, I look for the blessings and, guess what; I see more of them.
The human experience includes suffering in mind, body and spirit. We can conscious choose which direction it takes us. I can become bitter and resentful. Been there, done that, not fun. Or I can react to it with more empathy and compassion, and use it to be more deeply appreciate all the blessings in life. Choosing the latter, my life becomes richer and more enjoyable.
Ultimately Big Mind and small mind, God and self, Buddha Nature and ego are not separate things. The ordinary mind is an aspect of the universal that is conditioned by events and fears to a more limited perspective. As ordinary mind becomes more consciously identified with the higher self, Buddha Nature, or if you will, God, life’s possibilities open up.
Of course this is not really about eyes open or closed, but a grounding and joining of our inner and outer experiences in such a way to experience life as richer and more joyous.