Natyashastra
वलनं गमनं त्र्यस्रं पातनं स्रस्तता तथा । चलनं कम्पनं ज्ञेयं प्रवेशोऽन्तःप्रवेशनम् ॥ १००॥
Valana (turning)—moving (the eyeballs) obliquely. Pātana = Pāta (relaxing)—relaxation (of the eyeballs.) Calana (trembling)—tremor (of the eyeballs.) Saṃpraveśana = Praveśa (drawing inside)—drawing (the eyeballs) in.
english translation
valanaM gamanaM tryasraM pAtanaM srastatA tathA । calanaM kampanaM jJeyaM pravezo'ntaHpravezanam ॥ 100॥
hk transliteration by Sanscript