An iris dilator includes a body formed of an expansile material being expandable from a dehydrated first size and shape to a hydrated second size and shape. When hydrated, the dilator has a shape complementary to an inside diameter of the iris and a size sufficient to dilate the iris. In addition, a mammalian iris may be dilated by inserting the at least partially dehydrated iris dilator described above into a position radially inwardly from the iris where, in the presence of bodily or surgical fluids, the dilator hydrates and expands to engage and dilate the iris. An apparatus for deforming the dilator to facilitate insertion in use includes top and bottom surfaces which engage top and bottom sides of the dilator, respectively, at least one depression member for forming a depressed area on an edge of the dilator and at least one retainer member for retaining a non-depressed area on the edge of the dilator.