Is catching, or heading a ball challenging for you? If you’ve ever tried threading a needle, did it end in frustration? Have you ever thought of blaming your eyes for that? Two eyes that work together help you estimate how far a ball is or where the thread is with respect to the needle. This “working together” of the eyes happens in the brain. The brain receives two images one for each eye, processes them together with the other information collected and returns one image, resulting in what we see. Are you curious about how depth perception enters the picture?
We have two eyes, but we only see one single image. We use our eyes together (in synergy) to gather information about our surroundings. Binocular (or two-eyed) vision has many advantages; one of them is the ability to see the world in three dimensions. We can see distance and depth because our eyes are located at two different points, approximately about 7.5 centimetres apart, on our head. Each eye looks at every item from a different angle and registers a different image on its retina. The two images are sent to the brain where the information which is collected is processed and our brain, then brings one three-dimensional image. The three-dimensional aspect of the image allows us to understand length, width, distance, and depth between objects. Scientists refer to this as binocular stereopsis.
Some artists use binocular stereopsis to create a 3-D film and images. They show each eye a slightly different image. The two images show the objects as seen from two different angles, as would be when you saw the object in real life. For some people, it is hard to fuse two slightly different images presented at each eye; and others find it a bit easier. Their depth perception might depend more on other clues. They might find less pleasure in 3-D pictures, games or movies, and certain tasks such as threading a needle or playing ball might be more difficult.
Because we have 2 eyes, we get a wider field view of 180 degrees. Two eyes help judge the distance of an object more accurately.