Purity: Ruling on Washing Hidden Parts of the Face and Ignorance of the Rule in Wuḍūʾ
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 241
It is not obligatory to wash inside the nose or those parts of the lips and eyes that cannot be seen when closed. However, if a person is not certain that everything that must be washed has been washed, it is obligatory that he wash a little of those parts as well to be certain. Furthermore, with regard to someone who did not know this rule, if having performed wuḍūʾ he does not know whether he washed the required area or not, the prayers he performed with that wuḍūʾ are valid and it is not necessary for him to perform wuḍūʾ again for the next prayer.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)