1. The brown waste material deposited in skin and nerve cells that is commonly called "age spots." Lipofuscin is made of free radical damaged proteins and fats. 2. Fatty deposits in the retina which are thought to be toxic to retinal cells. A by-product of drusen. 3. The product of oxidation and polymerization of the membrane lipids of autophagocytosed organelles. 4. Lipochrome.