Amid the ongoing debate over the proper interpretation of Aristotle's theory of sense perception in the "De Anima," Steven Everson has recently presented a well-documented and ambitious treatment of the issue, arguing in favor of Richard Sorabji's controversial position that sense organs literally take on the qualities of their proper objects. Against the interpretation of M. F. Burnyeat, Everson and others make a compelling case the Aristotelian account of sensation requires some physical process to occur in sense organs. A detailed examination of the interpretation by Everson and Sorabji of Aristotle's theory, however, shows that their reading cannot be the correct one, since it involves many textual and philosophical difficulties. Their interpretation, for instance, would require abandoning Aristotle's requirement that only a transparent substance is suitable matter for an eye. Likewise, their understanding of the Aristotle's doctrine of sensation as the reception of form without matter in "DA 2.12" cannot be reconciled with other texts of his from "On Generation and Corruption." An analysis of these texts, as well as "DA 2.7" and "De Sensu 6" on the roles of light and the transparent medium in vision, show that, for Aristotle, the physical processes which sense organs undergo are not standard qualitative changes (i.e. alterations), but activities or the actualizations of potencies in the material constituents of living animal bodies.