Applying kohl, whether inside or outside the eyes, does not break wudu (ablution). The same ruling applies to other cosmetics that may be applied to the skin, such as creams, powders, or henna.

Shaykh Abd al-Aziz ibn Baz was asked about this matter and clarified that these substances do not nullify tahara (purity). He explained that the nullifiers of wudu are specific matters established by the Qur'an and Sunnah, such as passing wind, urine, or stools; deep sleep; and eating camel meat. Applying something to the surface of the skin is not among these established nullifiers.

Therefore, a woman may apply kohl or other makeup after performing wudu, and her wudu will remain valid. She can pray with that wudu as long as none of the known nullifiers occur.

It is important to note the difference between applying kohl after wudu and applying it before. If kohl or any makeup is applied before making wudu, one must ensure that it does not form a waterproof layer that prevents water from reaching the skin that must be washed. If it is waterproof, it must be removed before performing wudu for the ablution to be valid. However, if it is applied after a valid wudu has already been completed, it has no effect on its validity.