What is 3D Vision?
3D Vision is the ability to perceive depth and see the world in 3D. It relies on both eyes sending slightly different images to the brain, which merges them to create a sense of depth.
Some children are born with conditions like strabismus (eye misalignment) or amblyopia (lazy eye) which interfere with this process, leading to poor 3D vision, or even stereoblindness.
Why Do We Have Two Eyes?
At first, one might think it’s for depth perception—but close one eye, and we can still judge the spatial distances between objects quite well. In fact, some remarkable people, like cricketer Nawab of Pataudi and aviator Wiley Post (who was the first to fly solo around the world), excelled in their fields with just one eye. So why do we have two?
Rabbits have very limited stereovision with their eyes situated on either side of their heads. Tigers' eyes, like ours, face forward.
It's not just about having two eyes—it’s about how they’re positioned. Prey animals - like rabbits and pigeons - have eyes on the sides of their heads, giving them a wide field of view to spot approaching danger. Predators - like tigers and owls - have forward-facing eyes, just as we do. This forward-facing eye alignment allows for stereoscopic vision, where both eyes work together to detect depth and 'break through' camouflage—an essential skill for hunters.
Stereoscopic vision is very good at breaking camouflage
For humans, stereoscopic vision isn’t just about survival; it’s crucial for navigating the world, judging distances, catching a ball, or even pouring a drink. It’s a powerful ability and one we often take for granted, or underestimate the impact it can have for those who don't have it.
Why Binocular Vision Matters for Your Child
The ability of both eyes to work together to perceive depth— also called binocular vision - is crucial for many aspects of daily life. If a child has poor stereovision, they may struggle with depth perception, affecting everything from their performance in sports to their ability to read, write, and focus in school.
How We See in Bionocular Vision
The human visual system processes depth by integrating the slightly different images captured by each eye. These images are transmitted via the optic nerves, with the right eye's image primarily processed in the left hemisphere of the brain and the left eye's image processed in the right hemisphere. This occurs because the optic nerves partially cross each other, ensuring that visual information from both eyes is combined in the visual cortex at the back of the brain.
The brain analyses the disparities between the two images—the small differences in the position of the objects viewed and seen by the eyes—to calculate depth. This process, known as stereopsis (from the Greek stereos, meaning "solid," and opsis, meaning "sight"), allows us to perceive a three-dimensional world. By measuring these disparities, the brain constructs a detailed depth map, enabling precise spatial awareness and interaction with our environment.
