I acknowledge this picture from the Internet.

In this 53 verse of Vigyana Bhairava Tantra Shiva says:

Looking at the spread light 

Of the sun or a lamp

Illuminate own Self

One of the well-known techniques of dharana is to focus the sense of sight by looking at a lamp or any light for extended periods of time. Known as trataka, this technique of staring fixedly at a candlelight in the slightly unfocused manner, looking at beyond the candle, but with the light at center of vision, powerfully activates the ajna chakra, the eyebrow center.

Ajna is the master of all chakras. It connects to the pituitary gland that controls other hormonal glands. Ajna means command or will, signifying the ability to will anything to happen when activated. Along with this power can come arrogance. This twin capability of ajna comes through with the twin petalled lotus that symbolizes this chakra.

This technique, marginally different from trataka, essentially capturing the power to activate ajna, requires us not to focus on the light but the spread of the light around the source, especially relevant if one chooses to stare at the sun light and not go blind. The light activates the ‘eye’ and ‘I’ energy, good for both, when practiced correctly and understood.

Best to choose early morning or late evening to practice this with the energizing and not overpowering light of the sun and look through the clouds or even a diffusing smoked glass. The idea is not to hurt the eye, and to bring one’s full attention on what one sees. When i have worked with people using a candle and focusing on the ajna chakra as well in meditation, extraordinary insights have arisen as if in telepathy.