Ashtangasamgraha 32.13

32.13

śalākāḥ pañca kanakarajatatāmralohodbhavā aṅgulī ca |

tatrādye prasādane 'ñjane snehane ca |

madhyā lekhane |

antye ropaṇe |

mṛdutvādaṅgulyatra pradhānatamā |

ataḥ saruje 'kṣṇi saiva prayojyā |

śeṣā daśāṅgulā rājamāṣasthūlāḥ |

suślakṣṇāstanumadhyā mukhayormukulākārāḥ kalāyaparimaṇḍalāśca ||

The probes are five: made of gold, silver, copper, and iron, and the finger.
Among them, the first two are used for soothing and oleating collyrium;
the middle one for scraping;
the last two for healing.
Because of its softness, the finger is foremost here;
therefore, it alone should be used in a painful eye.
The others are ten fingers [long], thick as a royal bean,
very smooth, slender in the middle, bud-shaped at the two ends, and rounded like a pea.