Nasikagra Drishti Mudra
In Sanskrit, Nasikagra means "nose tip," Drishti means "gaze" or "focal point" and Mudra means "gesture." This practice is a Mana Mudra meaning "head gesture" practice and is described in the Hatha Yoga Pradipika, Gheranda Samhita as well as the Shiva Samhita.
With practice you can keep the eyes focused on the nose tip for long periods of time. Do not strain the eyes at all.
The duration of the practice can be extend over several months. This Mudra can be practiced at any time of the day, but the early morning or before bed is best.
Practice
Sit in a Meditative Asana or a comfortable seated position.
Relax the shoulders and bring the palms to the knees.
Roll the eyes down the inwards towards the tip of the nose.
Hold the gaze for a few seconds to start.
Close the eyes when strain in the eyes starts.
Open the eyes and bring the gaze back to the tip of the nose.
The six cleansing actions are intended to be the start of a Yoga practice in order to clean, strengthen, remove toxins and improve the flow of Prana through out the practitioner.
Yoga poses help to elongate and strengthen the muscles of the body as well as to calm the mind for the deeper spiritual practices of Yoga.
Breathing exercises are a great practice to remove carbon dioxide, increase lung capacity as well as being a good preparatory practice for the deepest spiritual practice of Yoga, Meditation.
The four body locks that makes up this practice give the practitioner the ability to hold or lock Prana in certain locations of the body. These practices also allow the practitioner to release blockages that may be holding the practitioner back.
The gestures in this practice include the whole body and are intended to awaken Prana, Chakras as well as Kundalini energy within the practitioner.
Meditation is the highest spiritual practice of Yoga which is why this practice is the most difficult practice to preform, but with correct knowledge and dedication, can be the most profound practice of Yoga.