How does vision works?

Although it's a very complex problem, there are some simple concepts that let us better understand it.
Our eyes act as sensors, getting the data, that data is then processed by the brain. We do not store images in our brain. After the ray of light hits your front eye, it's converted into neural impulses at the back of your eye. After getting the data from the eye, the brain creates the image based on the neural impulses (that act as symbolic descriptions of the image). These symbolic encodings are created partly in your retina itself but mostly in your brain. After being processed and transformed by the network of visual brain areas, you'll be able to recognize objects.
All of this processing happens in real time and it's effortless, without entering in our conscious awareness. ^[2][3]

Vision

Although we have a 180 degree peripheral vision, our field of vision at close range is 2 degrees. This means that our eyes focus on one point at a time with a lot of precision and detail. What we see is the result of several small focal points captured by the eyes that the brain then transmits as an image. In reality our eyes do not capture our peripheral vision in its entirety. The brain is responsible for creating this “illusion”. It's up to him to take those captured fragments and create an image that represents what we see at a peripheral level. That's why in our vision only a small percentage is focused and the rest looks a little blurry.

The movement and unreal objects/things capture more of our attention.

The explanation is “simple”. Humans are used to what the real world offers them, this makes the survival instinct always active, with or without this notion. If they notice something different or an apparently strange move, it triggers a reaction.

On a practical level, one of the examples is that, using certain pure colors (not common in nature) in contrast to more natural tone colors, unconsciously attracts the reader. In the same away, that a moving object attracts more attention than a stationary one.

One of the first things the human brain does after opening its eyes is to have a sense of the distance between the background and the proximity plane (background and foreground), as well as identify the limits / shapes of objects.

The human brain can detect shadow variations much faster than shapes. This lets you use contrast as a powerful tool if you want to easily distinguish something.

Visual perception

The human brain has several regions dedicated to visual perception. Through a network of groups of neurons dedicated to processing and filtering the information collected by our eyes.
Evolution in general, but more precisely technological, has been developed in such a way that no other activity requires a mental effort as great as visual and cognitive perception.

The brain doesn't just process information that is received through our eyes. It also creates visual mental images that allow us to think and plan actions that facilitate our survival.

Gestalt laws of perceptual organization

Also known as form psychology. It is a theory that the brain evolved to recognize patterns. When you establish equality between objects, you can better manage your energy and organization. Gestalt laws are derived from a study of patterns (gestalt) by a group of German psychologists around 1900.

These are the main principles:
- proximity: objects that are related to each other must be close together in the composition and aligned along the vertical or horizontal axis
- similarity: identical objects are perceived as belonging to a group
- connectedness: objects linked by visual elements are perceived as a group
- continuity: the continuity principle states that it is easier to identify a group of objects linked together through curved elements than straight ones
- closure: objects within an area limited by shadows or outline will be perceived as a group
These principles facilitate the absorption of visual information.

Visual comparison

The human brain identifies comparisons between objects in different ways depending on some details, such as shadows, angles etc... Thus it is possible to distinguish comparisons and rank them.

Vision is such a powerful element that modern psychology therapies are using it to cure traumas or reprocess memories. EMDR (eye movement desensitization and reprocessing) is one of these new methodologies.