Visual acuity is the sharpness or clarity of vision. It is the ability to see fine details at a given distance. Visual acuity is typically measured using a Snellen chart, which is a chart with rows of letters that decrease in size. The person being tested reads the letters aloud, and the smallest row of letters that they can read correctly is recorded as their visual acuity.
Good visual acuity is important for many everyday activities, such as driving, reading, and watching television. It can also be a sign of overall health, as some medical conditions can affect visual acuity.