How fast objects move across the retina provides a depth cue for the brain. You will still be able to gauge depth, just less accurately. If only one eye is sending depth cues to the brain, your vision becomes less three-dimensional. But monocular cues are still important and helpful. Monocular cues do not provide depth cues that are as accurate as binocular disparity. READ MORE: Convergence insufficiency: Causes, symptoms and treatment What are the monocular cues for depth perception? The extra effort to turn the eyes inward provides the brain with a depth cue.Ĭonvergence is a weak depth cue and is useful for objects up to 20 feet away. When you look at an object at a close distance, your eye muscles cause your eyes to angle inward. Otherwise, monocular depth cues must be relied on. Stereopsis requires that both eyes see clearly. It processes these two images as a single, three-dimensional image. The brain combines the clear images from the left eye and right eye. This difference is called “binocular disparity.” It is the most important binocular depth perception cue. The fact that our eyes are set about 6 cm apart results in slightly different images in the left and right eyes. Clear binocular vision is an important cue for the brain to calculate the distance and movement of objects around us. Our brain calculates depth from all the available cues the eyes receive from our environment. READ MORE: How does the brain control eyesight? What are the binocular cues for depth perception? Oculomotor – Depth cue from focusing on an object. The brain perceives three main types of visual signals, called depth cues, to create a three-dimensional image: The optic nerve sends this visual information to the brain. When we look around, our eyes gather information on the size, location, brightness, clarity and movement of the objects around us. The brain processes these images and interprets them as a three-dimensional representation of the world around us. Light rays enter the pupil and land on the retina, forming two-dimensional images.
Depth perception allows us to see the world in three dimensions and to judge the distance and movement between objects and ourselves.