Measuring visual acuity is not as simple as it seems

摘要

Measuring visual acuity is the most ubiquitous and useful test in the optometric armamentarium and one of the easiest tests to do. It is a good predictor of the presence or absence of refractive error and of a good number of sight-threatening ocular diseases. Visual acuity is vitally important for monitoring the progression of ocular disease. Reduced visual acuity after refraction signals the need to find an explanation. Visual acuity is a good measure of visual capability in everyday life and best of all, it is measured on an easy to understand scale.