Eyes moving upwards - mild lights - sense of space - pleasure

Hello Beautiful People, I have a quick question. After years of meditating with a mixture of Mahasi and Goenka style, I would like to ask the following. Very often when I sit to mediate, it is a matter of seconds to experience a subtle sense of pleasure and/or spaciousness. But more interestingly, is that after meditating a bit more there comes a feeling that my eyes want to move upwards, almost like if they want to see behind my head/brain. The first times this eye movement happened, years ago, there was fear in me because this was unusual and unexpected - it was even a bit painful. But after letting this movement happen I realized that the traditional lights, pleasure, and spaciousness became more present. Sometimes this leads to a very focalized pleasure spot at the top of my head and sometimes to the feeling that from that spot a very strong and interesting sense of pleasure would come from it (like if there is a cascade of pleasure emanating from the top of my head). The eye movement I am describing is not like REM. It is rather slow and it is directed upwards. So, I guess my question is: what is this eye movement thing? Is it anywhere described? Is it a Jhana thing? a symptom of any stage of the path? Thanks!