Mischna zu Wajikra 13:12

A priest who is blind in one eye or the light of whose eyes is dim should not inspect negaim; for it says, "Wherever the priest's eyes can see" (Leviticus 13:12). In a dark house one may not open up windows in order to inspect his nega.

The following places in a person do not become unclean on account of a bright spot: the inside of the eye, the inside of the ear, the inside of the nose and the inside of the mouth, wrinkles, wrinkles in the neck, under the breast and the armpit, the sole of the foot, the nails, the head and the beard; and a boil, a burn and a blister that are festering. All these: Do not become unclean on account of negaim Do not combine with other negaim, A nega is not considered to spread into them, Do not become unclean on account of quick flesh, And they do not act to prevent a person from being considered to have turned completely white. If subsequently a bald spot arose in the head or beard, or if a boil, a burn or a blister formed a scar: They may become unclean by negaim, But they do not combine with other negaim, A nega is not considered to spread into them, And they do not become unclean on account of quick flesh. But they do act to prevent a person from being considered to have all turned white. The head and the beard before they have grown hair, and warts with thin necks on the head or the beard, are treated as the skin of the flesh.