Meditation is all about energy body awareness. Our five physical senses and our physical body is not the whole of us, it is just a small part of the whole of us. But we get so engaged and absorbed with our physical senses and mental activity concerning these senses all the time that it is as if we are unintentionally turning a blind eye to the rest of the whole of our body, namely our energy body. You can read some of my other posts and answers to find out more about the energy body, here I shall confine to some suggestions with your experiences.
We may loose grounding even during a meditation practice and this causes the eyes to open. You can simply continue with the meditation with your eyes open for some time. What is important is eyeball movements. Even when the eyes are closed if there is a lot of mental activity instead of a quiet mind, the eyeballs will move and eyelids will pop open. You can fix your gaze on a spot in front of you and hold a gentle gaze with half open eyes and continue with the meditation. You can even gently begin rubbing your palms together and keep gently rubbing as you continue with the meditation or gently tap with the tips of your fingers at the spot under your eyes.
While doing these you can gently breathe in a style that supports the parasympathetic nervous system. After a few minutes you can go back to closing your eyes and continuing with the meditation as before. Meditation is a non-doing state of being. You are sitting as an aware witness to all that arises in the moment. Simply accepting and allowing all that arises to keep happening without seeking to react, respond or hold on to something or engaging with whatever arises. So what if the hands go invisible and energy rises? Simply be aware and let it happen as it is. If you get scared that your hands have really gone missing just open your eyes and check and then close and continue. It is just like when itching happens suddenly in the body somewhere, without thinking, our hands would go there and scratch and we can continue with the meditation uninterrupted.
The journey into your awareness that begins as you practice meditation takes you into the deepest aspects of you and this is something new for you. It is better not to exercise the analytical mind to examine each arising experience to see if you can believe it or not.
I would also suggest some deep grounding practices such as energy movements or gentle yoga stretches before sitting to meditate. You can find some very effective and healing movements practices in my YouTube channel.
Selvan Srinivasan
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https://www.youtube.com/channel/UCPPqfCV4_k9BWWcDz4_GzIQ
The Fixed Gazing and Conscious Breathing practice suggested in para three above is explained in the article linked below.

Selvan Srinivasan · 1y
What are some breathing exercises for beginners who struggle with focusing on their breath while meditating?
Do this for just three minutes and see if it helps. Sit on a straight back chair with feet flat on the floor, the entire soles of the feet from tips of the toes to the heels firmly contacting the floor. Keep your back erect, you may place a cushion behind your back for support if required but do not lean back on an inclined backrest of the chair. Let your head be held straight, neck straight, shoulders square and relaxed. You may tilt the head very slightly downward to gaze at a point on the floor in front of you a few feet away from you. Keep your eyes fixed on that spot for the three minutes without moving your eyeballs. Allow your eyes to be half open and half closed and hold that spot in a gentle gaze and not a stare. You are not looking there to see something but simply holding that spot in a gentle gaze. Exhale with a loud sigh from your mouth and use gentle effort to empty your lungs as far as possible without straining too much. Then relax your body and allow the inhale to happen effortlessly and soundlessly through your nostrils. When you sense that the inhale is over, do not put any further effort to breathe in but repeat the exhale from the mouth with the sound and gentle effort. I call this conscious breathing. Effort only for the out breaths and allowing in breaths to happen effortlessly. This entire process is called FGCB or fixed gazing with conscious breathing. You may set hourly reminder alerts on your smartphone and repeat this 3 minute FGCB every hour throughout the day today and see how it helps with calming your mind. This is a powerful grounding practice and you can do this even when you are driving and waiting for the red signal to turn green. Allow any such interruptions in your day to remind you to come back to the practice of FGCB repeatedly. For more information and plenty of free resources to aid with the practice of meditation and deep healing, please visit my website.