Screening for Visual Impairment

A TELEPHONE survey effectively screen for visual impairment?To what extent is a telephone sample representative of households where visual impairment is present ?Or, stated otherwise, will a telephone sample produce prevalence rates of visual impairment comparable to rates obtained by more tradi¬ tional sampling methods; for example, person¬ ally interviewing a sample of all households (telephone and nontelephone) as in the Na¬ tional Health Survey and most other health studies?Is there under-reporting of visual impairment in telephone screening as compared with face-to-face interviews?How much trust should be placed in what people say about their eye trouble?Can acceptable data on vis¬ ual acuity be obtained by nonmedical investi¬ gators conducting standardized vision tests in the homes of respondents ?These are the questions we sought to answer in a household survey of visual impairment.