Health-Related Quality of Life for Visually Impaired Older Chinese Adults

Abstract

Synonyms Vision loss; Visual functioning Definition According to the World Health Organization (WHO), the term “impairment” is defined as “any loss or abnormality of psychological, physiological or anatomical structure or function in the context of health experience” (World Health Organization [WHO], 1980). Therefore, impairment is a measurable loss or departure of functional capability, which is outside the normal range. Vision impairment refers to all degrees of vision loss and is both functionally based and measurement based. It is a measurable loss of visual function in psychophysical measurement. Clinically, visual function is often measured in terms of visual acuity, sometimes with additional criteria for visual field, color vision, and contrast sensitivity. Visual acuity is scored as a set of two numbers, e.g., 20/40, which indicates that the patient’s eye can only read from 20 feet letters large enough for a normal eye to read from 40 ft. Usually, 20/20 vision is .....