A method for prevention of migration of epithelial cells in a capsular bag of an eye of a mammal is provided. The method comprises removing the natural lens of the eye from the capsular bag; introducing an object with at least one sharp edge into the capsular bag, in such a way that said sharp edge contacts the inside of the capsular bag to form a barrier preventing migration of epithelial cells across said barrier; and injecting a lens-forming composition into the capsular bag.