Perception and perspective

Alastair Somerville
3 min readJun 11, 2017

I often work on interpreting art for people with physical and/or cognitive impairments. I was sent some work this week which included a big problem that is often hard to explain to people.

So I’ll try and explain it here and find out if you understand it. This is usability testing of an explanation.

Those clever Renaissance artists

Let’s go back to the Renaissance and an idea that everyone agrees was very clever.


Representing things in the distance as getting progressively smaller.

A way of visually organising information.

It solved the dimensionality problem of Medieval art. The flatness where objects all appeared in the same plane. Up or down, left or right.

And that’s all great.


It’s not true.

Things don’t get smaller in the distance. They are exactly the same size. Just further away.

The problem of having a sense of perspective

This lie underlies the problem of art interpretation I’m dealing with now.

Let’s say you have a painting with a scene of a city street and people walking around.

With perspective, this is all set up to line up with an imagined point in the distance. All the building and people heights are adjusted by lines of perspective to that far point.

This works if you have a consensus of people who see perspective.

However, I need to convert visual information to tactile information. This project is about interpretation for visually impaired people

Now some people will have had sight and know the rules of perspective. Some won’t and they won’t ‘know’ that things get smaller in the distance.

This is the problem of perspective.

Sight has unseen biases that only blindness can explore or explain.

All objects are the size that they are.

Often to explain a perspective painting, we use top-down view maps to show the street wand place the elements in the painting.

This maintains the relative size and position of objects. This allows a discussion of how things are passed through by person.

Obviously, maps are also a diagrammatic representation of physical relationships but this is about changing information presentation for different perceptions.

Respect different perceptions

This example is just about visual perspective and visual impairment but I could discuss music/audio design/hearing and graphic design/symbology/cognition.

I hope this explanation makes sense.

Its about how a consensus about a way of representing ‘reality’ can become so embedded that it is invisible yet overwhelming.

Everyone has different perceptions. We publicly agree to some shared ways of seeing and thinking. We keep private some ways that we individually perceive things.

We need to recognise that more often.

Respect each other and understand how the way we see is not necessarily ‘true’.



Alastair Somerville

Sensory Design Consultant, usability researcher and workshop facilitator. Twitter @acuity_design & @visceralUX