Natyashastra
सत्त्ववित्रासनोद्भूतं भयमुत्पद्यते नृणाम् । स्रस्ताङ्गाक्षिनिमेषैस्तदभिनेयं तु नर्तकैः ॥ २४॥
Fear in men arising from terrifying objects should be represented on the stage by actors (lit. dancers) with slackened limbs and suspended movement of the eyes. There is also an Āryā on this point:
english translation
sattvavitrAsanodbhUtaM bhayamutpadyate nRNAm । srastAGgAkSinimeSaistadabhineyaM tu nartakaiH ॥ 24॥
hk transliteration by Sanscript