Why is it not permissible to apply kohl inside the eye when leaving the house?

Every believing woman must conceal her adornment from non-mahram (definition) men, based on the Almighty's saying: (and not expose their adornment except to their husbands...). Adornment includes kohl, makeup, jewelry, and similar items. As for His saying: (except what is apparent thereof), it refers to clothes, abayas, and headscarves, or what appears unintentionally.

The principle is that a woman should cover her entire face, but she is permitted to uncover her eyes to be able to see with them, provided that exposing the eyes does not lead to temptation. The permissibility of wearing the niqab for a non-muhrimah woman is indicated by the Prophet's (peace be upon him) saying: (A woman in ihram (definition) should not wear the niqab, nor should she wear gloves).

The wisdom behind prohibiting the display of adornment is to safeguard the woman, preserve her chastity and dignity, close the door to temptation through her, and eliminate any desire to seduce her.

In summary, it is not permissible for a woman to appear with kohl in front of non-mahram men, because it is among the adornments she is commanded to conceal.