It is prohibited for a woman to wear false eyelashes because they come under the ruling of hair extensions, for which the Messenger of Allah (peace be upon him) cursed those who do that. Al-Bukhari and Muslim narrated that Asma’ bint Abi Bakr said: A woman came to the Prophet (peace and blessings of Allah be upon him) and said: “O Messenger of Allah, I have a daughter who is newly married, and she had the measles and her hair fell out. Can I give her hair extensions?” He said: “Allah has cursed the one who fixes hair extensions and the one who has that done.”

Al-Bukhari and Muslim narrated from `A’ishah that a girl from among the Ansar got married and she became sick and her hair fell out. They wanted to give her hair extensions, so they asked the Messenger of Allah (peace and blessings of Allah be upon him) about that, and he cursed the one who fixes hair extensions and the one who has that done.