Lash perming and lifting are cosmetic procedures. Lash perm involves curling the lashes with chemical solutions, carrying a risk of allergic reactions, while lash lifting typically includes keratin treatments with lower risk. In Islam, beautification aimed at attracting the attention of non-mahram men is not permissible (see Surah An-Nur, 24:31).
Lash lifting, if it poses no health risks, may be permissible, but since it creates a barrier preventing water from reaching the skin, it invalidates ablution (wudu) and ritual purification (ghusl). Therefore, unless medically necessary, it is not permissible. Lash perming, on the other hand, may be considered permissible if performed under medical supervision.