During meditation, I have experienced this phenomenon frequently for the past two months. Recently, it has been occurring about once every few days, and for a certain period of time, whether it's a few hours or even just an hour, when I meditate and reach a state of stillness, I experience the same thing.

If I recall, it clearly started about two months ago, although I think there were times before that when something similar happened. However, the feeling of something happening at the ajna (third eye) between my eyebrows started around that time. It coincided with the beginning of a strong aura permeating the area around my eyebrows and slightly above them. I felt as if the aura was being forced through a narrow path from the ajna, as if it were opening a small passage inside.

I have a sense that the aura is opening the energy channel to the area around my forehead and the center of my head, where the pineal gland is located. This channel was not as open before, and I feel that it started to open at the same time that the aura began to permeate my forehead.

When energy tries to pass through this channel, it's narrow and there are many obstacles. Every time energy tries to pass, my head, especially the area around my forehead, repeatedly loosens and creaks.

And when energy tries to pass through the ajna, even if it's just a little, it starts to flow from my forehead towards the center of my head. Although it's still a narrow channel, the area on my forehead, which I believe corresponds to the ajna, starts to tremble rapidly, about twice the rate of my pulse. I think this is a vibration caused by the energy starting to flow.

It feels like a vibration, but depending on how I perceive it, it's as if the area on my forehead is "blinking" very rapidly and repeatedly, like a normal eye blinking at twice the rate of my pulse (not a full blink, but a rapid half-open blink). Even though there are no physical eyes on my forehead, I feel like I'm experiencing that sensation in the area between my eyebrows.

This type of "vibration" is also described in yoga texts.

"The ajna chakra begins a very refreshing and subtle vibration." (Esoteric Yoga P207)

According to this description, it is a phenomenon that occurs during the initial stages of the ajna chakra (third eye) awakening.

However, this type of vibration seems to be occurring in a state that is moving from the subtle energy dimension to the astral dimension, and it doesn't seem to be a very high dimension.

Perhaps, in my case, Azuna was sealed. I think that for other people, it might awaken gradually and synchronize with other chakras, but in my case, it might be that the seal in this area will be released all at once.

Probably, it's not good to force the seal to open with too much force, so I have a feeling that my own spirit, which is watching over me, will release the seal at the right time when it has reached a certain point.