Does ablution (wudu') or ritual purification (ghusl) become invalid if the face is washed by leaving the eyelids untouched for fear of touching them, and sufficing with splashing water on them without touching, due to keratoconus?

It suffices to pour water over your face from above while your eyes are closed; the water will reach the outer surface of the eyelids. Washing the inner part of the eyes is not required in ablution (wudu') or ritual bath (ghusl (definition)) after major impurity (janaba), according to the consensus of the majority of jurists.