Hypnagogic Imagery Whilst Meditating

[Ish]

Hello guys, I used to post here before, but I kind of stopped lucid dreaming for awhile. I just had a question, and I decided this would be the best place to ask. Now, recently, I've been doing meditation. Now, I'm not a spiritual guy. I'm an atheist. However, I do meditation to both relax, and to become more present to the moment. Now, when I do it. I just lay on my bed and alternate between eyes open and eyes closed. I usually do eyes closed, until the chatter in my mind slows down, and then I do eyes open. Well, I had my eyes closed, and I was focusing on my breathing, but then like, I can't explain it, but my awareness shifted to what felt like the top of my head. It felt like I was enveloping my own mind. I can't really explain it. So, then I opened my eyes, and saw hypnagogic imagery. I was seeing swirling colors, and my body was losing feeling. I'm curious as to what this was. I'm hoping the meditation folks of the forums could help me. Now, I posted this here, because I know a lot of folks on here do meditation. I posted it in this section, as I see this being related to the WILD. I am only baffled, as I had my eyes open, and I was seeing the swirling colors and stuff. I also wasn't in sleep paralysis. Is it possible to experience the beginning stages of sleep paralysis with your eyes open or something?