We stumble our way through reality with the help of our nervous system. Our brain creates a simulation for us from the data collected by our senses. One can just wonder, wouldn’t it be fascinating if we had more senses? Or what if our senses would be just slightly more sensitive?

Let’s say we could perceive a slightly larger range of the electromagnetic spectrum with our eyes. How would seeing heat affect our everyday lives? How would it affect our user interfaces? Imagine how it would affect our fashion.

I think our most fascinating sense is vision, and it is also the one that is responsible for our perception of design and art.

Since our profession as interface designers relies so heavily on vision, wouldn't it be interesting to know more about the subject? It might not make us better designers, but it could increase our empathy and provide some inspiration!

A great source of inspiration for many has been the eye. It is such a beautiful and elegant organ and has inspired many artists, poets and writers through the ages. We are all familiar with the phrase “eyes are the window to the soul”.  But not only the eye itself, but its connection to the brain is even more interesting.

That connection is the key to understanding vision, but first let’s start by taking a closer look at the eye.

The Human Eye

As we always considered ourselves to be the greatest creatures in the known universe, we considered our eyes to be the most complex optical organs on the face of the Earth. Turns out that the Sun does not revolve around us, and our eyes are not even close to being the most complex in the animal kingdom.

Not the most complex, not the best, not the biggest, not special in any other way. Yeh, it’s a bummer. I know.

But there is good news.

We have the most complex brain, and a can-do attitude which makes up for our shortcomings. There is a connection between the complexity of the brain and the optical sensory system.

Generally, the more simple the brain is, the more complex the eye (eg. Insect eyes contain multiple lenses and receptors).

It is our most important sensory instrument for gathering data. Although, this fascinating instrument did not evolve with our species. It has been around long before us, and it required hundreds of millions of years of evolution for it to reach its present stage. The first “eyes” were not more than a cluster of photosensitive cells connected to locomotive devices. Thus, the detection of light or heat might have activated an appendage that moved the creature away from, or toward the stimulus.

Our eyes and brains are ancient instruments, they were not made for seeing and understanding art and design, but their purpose was to comprehend light, contours, contrast and movement. We have to keep in mind that we use these ancient instruments to view, analyze and understand art and the universe.

I would like to ask you now to look around your room and be conscious of your vision. You will notice that the area in which you have clear vision is actually really small.

That part in your vision with which you can focus is called foveal vision. The fovea is a dense cluster of light receptor cells on your retina. I will not get deep into the biology of the eye with this article, but there are some elements that are good to know in order to understand why our vision gets more and more blurry at the side of our visual field. The light receptor cells in our eyes get less and less dense as their distance increases from the fovea.

“It might be said that by moving from the center of the human retina to its periphery we travel back in evolutionary time; from the most highly organized structure to a primitive eye, which does little more than detect movements of shadows. The very edge of the human retina . . . gives primitive unconscious vision; and directs the highly developed foveal region to where it is likely to be needed for its high acuity.” — Richard L. Gregory

Because our sharp vision is so limited and restricted to a very small area, we view paintings, designs (and other objects) by constantly refocusing on different areas.

The perception that we see an image all at once is mistaken. We form an impression by a series of eye fixations that examine the detail within the foveal vision. Our eye muscles are constantly contracting and relaxing. While you can bring this activity under conscious control it is mostly automatic, just like the way you breathe.

You can hold your breath or consciously control it, but as you move your attention away your body just gets back to doing its thing. The movements of the eye are called saccades, and they were studied during the last century by French ophthalmologist Emile Javal in relation to reading. While reading we have about two or three saccades per second, although patterns of saccadic activity can vary widely for every person and for one individual at different times.

The data collected by our eye is transmitted to the brain for further processing. While our eye processes information sequentially, our brain has a much more interesting approach to this. In fact, it is the most interesting  information processing we have ever observed.

The Human Brain

The human brain is by far the most complex system that we know of. Just like our eyes, our brains barely changed anything in the past 30,000 years. We are basically using the same tools to create and perceive user interfaces as our forefathers did to create cave paintings.

While we have thousands of years of experience with art, we have started to explore the brain just over a hundred years ago. However, we now know quite a lot about it, including functions like understanding and appreciation of art.

Very often, the meaning of the words mind and brain become muddled. While the brain is an organ which is part of our central nervous system consisting of billions of neurons, the mind is what the brain does.

“Mind,n. – A mysterious form of matter secreted by the brain. Its chief activity consists in the endeavor to ascertain its own nature, the futility of the attempt being due to the fact that it has nothing but itself to know itself with.” — Ambrose Bierce, The Devil’s Dictionary

For a long time the brain was thought to have certain functions localized in precise regions. However recent studies show that there is something much more fascinating than that happening inside the brain. The brain is processing information by activating multiple areas simultaneously.

This process is called massive parallelism and the theory states that the brain distributes impulses throughout large portions of itself in a parallel fashion, instead of using a series of steps in which one neuron passes information on to another.

This explains how we are capable of recognising and classifying visual elements in such a short period of time. If the brain would work by passing information from one neuron to another, we would need many minutes to make sense of an object — if such an operation was even possible.

From all evolutionary success stories of organic systems none is more spectacular than the eye and the brain. The eyes are directly “wired” into the brain in a crossover fashion. The optic chiasm of the eye is passed on to the visual cortex on the opposite side. This crossover effect is called contralaterality and it is consistent with other brain-body functions also.

For example a patient with a stroke affecting the right hemisphere may have paralysis on the left side of her body. The structure of your eye and brain does not differ from the structure of my eye and brain, however the artistic impressions may vary widely.

You may like Rembrandt and I may like Picasso. Both of our perceptions are influenced by expectations, beliefs and cognitions. In some cases we may be aware of these influences, but in other instances this process occurs without us being consciously aware.


This was a short summary to better understand how vision works and keep in it mind (wink wink) whenever we're designing something. The topic of visual cognition fascinates me, and I hope I could spark your interest as well. Will this knowledge technically improve your skills? Nope. But maybe it will give you the push to be excited about the subject and try to implement it into your work somehow.

I am not trying to demystify art and design, or kill the magic of it, but to understand it from a different perspective. I heard someone say that just because you know the ingredients of chocolate, it does not mean that you can’t enjoy it. I agree with that. And you can even improve the ingredients or adjust them to perfectly match your taste.

Recommended reading:

  • Robert L. Solso – Cognition and the Visual Arts
  • Margaret S. Livingstone – Vision and Art: The Biology of Seeing
  • Rudolf Arnheim – Art and Visual Perception: A Psychology of the Creative Eye


Andrei Gaspar, Research and Editing.