What is the main purpose of visual acuity testing?

The main purpose of visual acuity testing is to measure the sharpness or clarity of vision. This testing is essential in determining how well a person can see at a distance, which is typically assessed using standardized eye charts that feature letters or symbols of varying sizes. Clinicians use this information to diagnose refractive errors, monitor changes in vision, and evaluate the effectiveness of any corrective measures being employed, such as glasses or contact lenses.

Visual acuity testing primarily focuses on the central vision capabilities of an individual, as opposed to peripheral vision assessment, which evaluates the side vision and is addressed through different specialized tests. Similarly, color perception and eye movement assessments serve distinct purposes in eye examinations and do not directly measure the clarity of vision. Hence, option B accurately reflects the core objective of visual acuity testing.