The inner eye sees.

"The light that sparks into being when the eyes blink
is witnessed by the single eye between the brows.
That eye is the place where the elements merge -
all the elements of your being."

"Consider how lightly the eyelids touch the eyes
with each blink.
That lightly, place the fingers over the eyelids,
and become aware of the space between these two exquisite centers of seeing.
There is the singular eye, which sees into a different world."

"With this eye, you can see very well
by the light of the inner fire.
The fire that is always flowing up the channel,
the medial channel of the spine.
Enter the core of any spark of that fire. "

"Be rooted in your heart, connect even to the tips of your hairs,
and attend the birthing of the light within you."

from Vijnana Bhairava

Making your mind imperturbable = inner mastery.