[Self-reported vision in (gerontological) health services research and practice-an opening plea].

The use of self-reported vision is an integral part of most population surveys and is primarily used for healthcare monitoring. Since the patient's assessment is not always consistent with the objectively measured clinical parameters, the majority of the literature looks critically at the adequacy of self-reported vision, particularly with respect to answering epidemiological questions; however, it is often misunderstood that self-reported vision measures far more than the directly derived information show. This article shows the complexity of self-reported vision and discusses the importance of health services research and practice, with a special focus on the topic of vision in old age. From the explanations it becomes clear that the self-estimation of vision by a person is determined by various factors apart from the pure organ function and that the need for action and diagnostic conclusions can only be derived from self-reports. This is essential if vision is to be understood as a multifactorial condition and empirically practiced using different survey instruments. The article shows that self-reported vision is a good indicator of the quality of care in its entirety.