Final answer:
Binocular vision requires two functioning eyes with slightly different vantage points that allow the brain to merge these perspectives into a three-dimensional image, providing depth perception.
Step-by-step explanation:
In order to have binocular vision, the ability to blend separate images from each eye into one coherent visual perspective, it is necessary to have two eyes that are positioned to provide slightly different angles of the same scene. Each eye captures its own view, and the brain merges these into a single three-dimensional (3D) image, allowing us to perceive depth. This phenomenon is known as depth perception and is crucial for tasks such as coordination, grasping objects, and generally navigating the three-dimensional space of our environment.
Beyond the natural world, the concept of binocular vision can be exploited in technology, such as in 3-D movies. Here, two-dimensional images are presented differently to each eye through special glasses, simulating the effect of binocular vision and creating an illusion of depth in a movie theater setting.
In summary, binocular depth cues, like binocular disparity, signal the subtle differences in views between our two eyes, and these cues are fundamental for humans to perceive depth and experience the world in 3D.