समं कायशिरोग्रीवं धारयन्नचलं स्थिरः ।
सम्प्रेक्ष्य नासिकाग्रं स्वं दिशश्चानवलोकयन् ।। ६.१३ ।।

samaṁ kāya-śiro-grīvaṁ dhārayann-acalaṁ sthiraḥ |
samprekṣya nāsikāgraṁ svaṁ diśaś-cānavalokayan || 6.13 ||

Krishna then gives a discipline to the eyes, which are the most sensitive and active of all our senses (6.13). From the moment we wake up from sleep, our eyes are always engaged till we sink in sleep again. As long as the eyes remain open, seeing will continue and controlling the mind will be difficult. To close the eyes is not a common habit. Many may find it difficult too. Krishna cleverly treats this hardship. “Keep the eyes open,” he says, “but look at the lower or upper end of the nose”.

In both cases nothing will be seen, as both the points will not fulfill the requirement of the least distance for distinct vision. To make doubly sure that seeing is fully avoided, Krishna adds that no attempt should be made to look in any direction at all. How clever a way of disallowing all kinds of vision, yet keeping the eyes open!