Binocular disparity refers to the slight difference in the images that each eye perceives due to their horizontal separation. Each eye views an object from a slightly different angle, which creates two distinct images. The brain processes these images to create a single three-dimensional perception of the environment. This difference in visual input is crucial for depth perception, allowing us to judge distances and the spatial relationship between objects. When the brain combines the two images, it helps us understand how far away things are, enhancing our ability to navigate and interact with the world around us.