Murdha the head
Jyotisi on the light
siddha the perfected beings
By performing samyama on the light of the crown of the head (fajna cakra), the yogi has visions of perfected beings.
Siddhas are those who have perfected themselves in the field of enlightenment. Murdhajyoti represents the ajha cakra of the yoga texts.
A yogi can develop a balanced head and a poised heart, and from his visions of siddhas, yogis and acharyas (great teachers) he may obtain guidance and inspiration to further his sadhana.