Peel the eggplant and then slice it thin. Beat together the eggs and water in a shallow dish. Dip the eggplant slices in the egg and then into the breadcrumbs and coat evenly. Heat the oil over medium heat in a heavy pan. Fry the eggplant slices until lightly browned. Coat the bottom of a baking dish with some of the tomato sauce. Make a layer of eggplant over the sauce. Spread some of the Ricotta cheese over the layer of eggplant. Top with some more sauce. Repeat these layers until you use all of the eggplant. Spread the mozzarella cheese over the top. Bake in a 350 degrees F oven for about 30 minutes.