Manasara 65.37

65.37

ūrdhvādho varmavistāraṃ dvyaṅgulārdhaṃ trimātrakam
matsyākārākṣimātraṃ syād bhruvaḥ kodaṇḍavatsudhīḥ

The width of the upper and lower eyelids is two and a half to three units. / The shape of the eye should be like a fish; the wise artisan [should fashion] the eyebrows like a bow.