I have not heard about a strong connection between cataracts and insulinoma. The development of cataracts with the antithesis of insulinoma, i.e., diabetes mellitus, is well known. The mechanism behind this is the elevation of glucose in the eye, which slowly diffuses into the lens. For this reason, the lens takes on water, and the cells of the lens balloon and disrupt, resulting in a cataract. Not many ferrets actually have cataract removal surgery, as these are poorly sighted creatures, and the possibility of retinal disease may make cataract surgery an exercise in futility. A visit with a veterinary opthalmologist however, may do well to outline your options in this case. With kindest regards, Bruce H. Williams, DVM, DACVP Join the Ferret Health List at http://groups.yahoo.com/group/Ferret-Health-list [Posted in FML issue 3438]