An introduction to Visual ergonomics What is visual

An introduction to Visual ergonomics

What is visual ergonomics The design of the visual environment + the physiological, cognitive and other responses to the visual environment

What can be modified in the visual environment? • Illumination • – – – Brightness Colour Flicker – – Angle Contrast Frequency Area • Frequency • modulation Pattern • Design of task – Central vision – Peripheral vision – Mapping and sequencing

The evidence of effect is compelling But a lot more research is needed

What effects do modification of illumination have? • Brightness – Implicated in glare, headache, inability to read, tearing, sore eyes • Colour – Implicated in dyslexia, dyspraxia, dyscalculia, dystonia, hearing difficulties, vestibular problems, short term memory difficulties, eye movement problems, peripheral field reduction, attentional field changes, changes in occipital cortex and more • Flicker – Epilepsy, migraine, headaches

Pattern • Angle – position relative to eye – Implicated in mapping problems, jump convergence and executive control of eye movement. Horizontal / vertical mapping important in design. • Contrast – Greater contrast generally worse but colour contrast may cause even more problems. • Frequency – Spatial effects dependent on distance ( angular subtension is important) • Area – the larger the area = more potential problems

Task design Central vision form – reversals and inversions of letters size – eye movement and span background Peripheral vision movement – pattern glare “clutter” - crowding Mapping and sequencing order and timing – displacement, chromostereopsis, instability of text, synesthesia?

Clinical evidence A simple introduction

What do these mean? • All performance criteria are affected by the visual environment • The effects are physical, measurable and quantifiable • In special needs effects are even more pronounced • The status quo is unacceptable

We can also provoke the following symptoms experimentally

It is intolerable that so many symptoms can be produced by the environment To ignore this is negligent

The future • Architects need to change room design in schools, • • homes, offices health and safety, duty of care, disability acts CIE regulations need changing Task design e. g. in exams needs to take visual ergonomics into account – how long before litigation? – A minefield? !!! Assessments and reasonable adjustments need to be made for anyone with potential difficulties – Who is to assess?

What we need to do • More research to determine optimum design of buildings • Modify environment and task • Take into account special needs / vision problems • Bespoke responses when required