Some people follow a “Jyoti mudra”
They see light ! Yogananda describes it god talks with Arjuna in chapter 6
What he described is phosphene. Flickers if light. They are partly divine light but not completely. They tend to disappear quickly. It is a good start
So when can you see true light in its full effulgence ?
When thoughts go away. Including the thought that you meditate or the thoughts you have a body
It is remarkable when you get it! Not One in a billion races it. Some reach jada samadhi but that means nothing
Bhavin