[Several common biases and control measures during sampling survey of eye diseases in China].

Bias is a common artificial error during sampling survey in eye diseases, and is a major impact factor for validity and reliability of the survey. The causes and the control measures of several biases regarding current sampling survey of eye diseases in China were analyzed and discussed, including the sampling bias, non-respondent bias, and diagnostic bias. This review emphasizes that controlling bias is the key to ensure quality of sampling survey. Random sampling, sufficient sample quantity, careful examination and taking history, improving examination rate, accurate diagnosis, strict training and preliminary study, as well as quality control can eliminate or minimize biases and improve the sampling survey quality of eye diseases in China