Which depth cue relates to how sharply an image is focused, affecting depth perception?

• A. Size
• B. Focus
• C. Texture
• D. Occlusion

Answer: (B)

Depth perception can be informed by how sharp or blurred things appear. When an object is in focus, it looks clear, and our eye’s lens has adjusted to that distance. If another object sits at a different distance, it will tend to be blurrier. The brain uses this difference in sharpness, or focus, as a cue to judge how far away things are. That focusing-based cue helps us perceive depth even with one eye, and it complements other cues we use, like size, texture, or occlusion. The other options describe different ways we gauge distance—how large something seems, how detailed its surface texture is, or whether one object covers part of another—none of which rely on the sharpness of the image.