Fell off (apepesan). Second aorist active indicative (note - an ending like first aorist) of apopiptō, old verb, but here alone in the N.T.
As if it were scales (hōs lepides). Chiefly late word (lxx) from lepō, to peel, and only here in the N.T. See Tobit 11:13, “The white film peeled from his eyes” (elepisthē). Luke does not say that actual “scales” fell from the eyes of Saul, but that it felt that way to him as his sight returned, “as if” (hōs). Medical writers use the word lepis for pieces of the skin that fall off (Hobart, Medical Language of St. Luke, p. 39). Luke may have heard Paul tell of this vivid experience.
Was baptized (ebaptisthē). First aorist passive indicative. Apparently by Ananias (Act 22:16) as a symbol of the new life in Christ already begun, possibly in the pool in the house of Judas as today water is plentiful in Damascus or in Abana or Pharpar (Furneaux), better than all the waters of Israel according to Naaman (2Ki 5:12).