What does the Snellen acuity chart measure?

The Snellen acuity chart is specifically designed to measure visual acuity, which refers to the clarity or sharpness of vision. It typically consists of rows of letters or symbols that decrease in size, allowing the clinician to assess how well a person can see at various distances. The test is standardized, with results usually reported as a fraction, such as 20/20, indicating the clarity of vision compared to a standard reference. This makes the option regarding visual acuity the most appropriate choice.

Peripheral vision, color vision, and depth perception are distinct aspects of visual function measured through other specific tests and methods rather than with the Snellen chart. For instance, peripheral vision is assessed through a confrontation visual field test or automated perimetry. Color vision is evaluated using tests such as the Ishihara plates, and depth perception is often assessed using stereopsis tests. Therefore, focusing on the ability to see detail at a distance is the hallmark of the Snellen chart's purpose, confirming visual acuity as the right answer.