In ABV, sensory fusion refers to:

• A. The perceptual fusion of two slightly different images into a single image.
• B. The retinal processing of color signals.
• C. The mechanical alignment of the eyeballs.
• D. The reflex blinking pattern.

Answer: (C)

Sensory fusion in ABV is the perceptual merging of the two slightly different images from each eye into a single, unified image. This happens when the disparities between the images are small enough that the brain can match corresponding retinal points and fuse them, giving a single, coherent view and enabling depth perception through stereopsis. It’s a perceptual process, not a motor one—the actual movement and alignment of the eyes (vergence) are separate motor actions that position the eyes but do not constitute fusion itself. If the disparity is too large or one eye’s input is suppressed, fusion does not occur, leading to double vision or suppression. The other options describe color processing, mechanical eye alignment, or reflex blinking, which are different processes and do not capture the perceptual merging at the heart of sensory fusion.