I think there is a correlation like this. When I meditate and pass energy through the root of my nose, and the forehead and inside of the head vibrate or energy flows through them, I can see a certain amount of light even with my eyes closed.

In classical yoga texts and various books, it is often described as "a light like a dazzling sun." In my case, I don't feel dazzled just because I see light, but I simply feel a light of a certain intensity, so I don't know if it's exactly the same as that description, but it might just be a difference in expression, and it could be the same thing.

Also, some books describe that light appears when the chakras open, as a temporary phenomenon. In my case, I see light when energy flows through my forehead, which is a correlation, and it doesn't seem like my chakras are fully open yet, so perhaps it becomes a more intense light when they open. Even if it doesn't, I can see a faint, appropriate amount of light.

Furthermore, some schools of thought state that light appears during meditation. In those teachings, it is said that this light is not of great significance, so it should not be worried about or ignored.

In other meditation teachings, light is described as "tan-ko" (inner light).

In some teachings of yoga, it is said that light emanates from the ajna chakra, allowing one to see things extrasensorially and astrally.

There are schools of thought that consider the light to be meaningful, and those that do not. Based on my understanding, it is as follows:

Light is extrasensory vision itself, as the ajna chakra. It is the light for astral vision. When an energetic pathway (nadi in yoga) is created and opened from the forehead to the center of the head, the ajna chakra and pineal gland, light appears. Some people may have it somewhat open from the beginning, so they may see a certain amount of light when they close their eyes. If that light becomes stronger, it may open extrasensory vision even when the eyes are open. Alternatively, even with the eyes open, that vision may appear outside the field of view. Therefore, when trying to see something extrasensorially, moving the eyes widely outward makes it easier to use extrasensory vision outside the normal field of view. However, in reality, the physical eye and the extrasensory eye are different, so once you get used to it, you don't need to move the physical eyes.

According to the writings of Honzan Hirasawa, seeing strong light indicates the "karana" realm (causal realm). Even in the astral realm, which is one step below, there is a certain amount of light, but dazzling light is said to be from the karana realm. The light or color of the astral realm is described as dark purple in the lower astral realm and light purple in the upper astral realm. Another description states that the upper astral realm is a pitch-black color mixed with light. In either case, the astral realm seems to have the characteristic of being dark.

The astral realm is essentially the realm of emotions, with joy, anger, sorrow, and delight. On the other hand, the karana realm is a pure and light-filled world. Even in the karana realm, it is not yet enlightenment, but it is still moving away from the astral realm and closer to purity.

The light of the karana realm can be perceived when energy enters the ajna chakra.