Introduction: perspectives on healthy aging.

The lenses with which we view aging are formed by many things: the maturing of gerontology as a discipline, the development of our theoretical and methodological tools for examining age and aging, and population aging itself. ‘‘Healthy aging’’ has become one of those lenses. For many years our attention has been drawn to the frailties associated with aging as we attempt to alleviate the suffering associated with age-related illness and disability. The late-twentieth-century addition of health-oriented models of aging has added a new dimension to the focus and language of our enquiries. Healthy aging, aging well, and successful aging now are part of the lexicon of gerontology.