The competence model of aging emphasizes transactions between the person and his/her environment. Adaptation of the environment to the person's resources gets equal status to the adaptation of the person to environmental demands. This becomes relevant for persons in need of help and care. Adapting their environment leads to a reduction of their environmental docility. It also becomes relevant for persons with higher potentials: Optimizing their environment contributes to environmental proactivity. For all groups, an increase of quality of life is correlated to optimized environments. While human factors design has created favorable conditions in the work place for many persons, it has not been applied often to the construction of home environments and to the production of equipment for everyday use. Results from a study on "Chances for and limitations of independent life in old age" are presented. They prove that elderly people in the new states of the Federal Republic of Germany not only differ from those in the old states with regard to the help and care they need. In the new states, environmental factors contribute considerably to limitations of independent life. Potentials of an optimally designed environment for the reduction of help and care are utilized even less in the eastern states of Germany than in the west. Arguments for the design of the furniture, equipment for communication and transportation, etc. are presented which emphasize ergonomic principles. They require that products should be adapted to the sensory potentials of their users, that they should allow an understanding or an easy cognitive processing of their functions, and that they should match the motor potentials of persons handling them. In short, products should be designed for a use that matches the "human model" as closely as possible. Thus, they will contribute to enhance the environmental proactivity of elderly people.