What is visual acuity?

• A. The sensitivity of the eye to color
• B. The ability of the eye to resolve fine detail
• C. The depth perception
• D. The perceived brightness

Answer: (B)

Visual acuity is the eye's sharpness, its ability to resolve fine detail. It describes how well you can distinguish small features and edges at a standard distance, which is what a Snellen chart measures—the smaller the letters you can read, the higher the acuity. This matters in liquid penetrant inspection because clear, precise vision helps you see tiny surface features or defects. The other aspects describe different visual attributes: color sensitivity is about color perception, depth perception is about judging distance and three-dimensional structure, and perceived brightness is about how bright something appears. Visual acuity specifically targets the ability to discern fine detail.