मोचनं नेत्ररोगाणां तन्दाद्रीणां कपाटकम् । यत्नतस्त्राटकं गोप्यं यथा हाटकपेटकम् ॥ २.३२ ॥

mocanaṃ netrarogāṇāṃ tandādrīṇāṃ kapāṭakam । yatnatastrāṭakaṃ gopyaṃ yathā hāṭakapeṭakam ॥ 2.32 ॥

Trâtaka destroys the eye diseases, because wherever the door is opened to light, darkness disappears. This secret should be closely guarded, like a box of jewels.