THE BLOODS USED TO PAINT EYES
What is Barkis?
Rashi: It is a white stain in the eye that protrudes.
Etz Yosef citing the Aruch: It is a Ru'ach that seizes the eye, and he cannot see.
What is Yarod?
Rashi #1: It is Tavlul (white that interrupts in the iris, and enters the black - Bechoros 38b).
Tosfos: This is unreasonable. Regarding this, the Tosefta says that blood is used to paint Churvar (NOTE: i.e. this is Yarod), and Bechoros 38b lists Churvar and Tavlul separately!
Rashi #2: They are small white dots in the eye, like it says in Bechoros 38b.
Etz Yosef citing the Aruch: The text is li'Yrod. A crust arose on the eye.
What is Kerushtina?
Rashi: It is a bat.
Etz Yosef citing the Aruch: It is a domestic chicken.
What is the Siman 'inside is for inside, outside is for outside'?
Rashi: Bats are found in settled areas; Yarod is recessed into the eye. Wild hens are found outside; Barkis protrudes from the eye.
Etz Yosef citing the Aruch: Domestic chickens found in the house are for Yarod, which is recessed into the eye. (Wild hens found outside the house are for Barkis, which protrudes from the eye.)