Today is World Sight Day 2019. Right now, more than 1 billion people cannot see well because they don’t have access to glasses, about 36 million people are blind, and 217 million people have moderate to severe vision impairment.
There are many widely recognised advantages to communicating data, information, and research visually, and a great number of tools available to create visualisations. But how do we ensure that our communications are accessible to this huge group of our global society? How do we visualise for those who cannot see?
Visualisation professionals have been asking themselves these questions, and it has led to some incredibly innovative and interesting work. Here and here data journalist Mona Chalabi experiments with integrating visualisations and audio to create an ‘audiochart’. Mona also collaborated with musician and writer Emmy the Great to develop an accessible art installation in Hong Kong called ‘Migrant Workers: Seen and Heard’. The data could be touched, heard, and felt by people who were partially sighted or blind.
Here are a few simple guidelines to ensure that your communications are as inclusive as possible:
- Reframe the way that you think about every visual communications product, and about who is being excluded from using this product. Use this opportunity to come up with innovative ways to include all audiences.
- When working with stakeholders, ensure that visually impaired stakeholders (and stakeholders with other limits to accessibility) are included in conversations.
- Ensure that all images posted online have alternative text. Alternative text provides a textual alternative to non-text content in web pages (e.g. pictures, charts, infographics) that describes the content and function of images. This is read aloud by screen readers used by those with impaired vision.
- Develop audio examples of visualisations when possible.
- Use colour pallets that have significant contrasts, and that still work for people who are colour-blind.
- Leverage shapes and texture to convey information, and not just colour. For example, use different patterns to distinguish between the bars on a bar chart, as well as colours.
- Label the different elements of graphics, so that they are easier to interpret if colour or vision is an issue.
And here are a few tools to help along the way:
Inclusive Design Toolkit: This free toolkit provides information and advice about different aspects of visual design, and how to ensure that the information is accessible to people with sight difficulties.
Audiochart: This free tool is still in its very early stages. It allows website designers to integrate audio into the charts on their websites, thus allowing users to explore charts on web pages using sound and the keyboard.
Highcharts: A free version of this tool is available. The tool helps users to create charts which have integrated accessibility support for visually impaired users, such as allowing keyboard navigation and basic ‘sonification’ (integrating audio into charts).
ColorBrewer: This free online tool helps designers to select colour schemes for maps and graphics. The colour schemes have been created to ensure maximum readability. They contain colours that are easy to differentiate and distinguish, even for people with some sight difficulties.
Color Oracle: This free colour-blindness simulator shows designers in real time what people with common colour vision impairments will see.
Spectrum: A free Google Chrome extension that instantly tests your web page’s accessibility for different types of colour deficiency.
Funkify: A free Google Chrome extension (with optional premium purchases) that simulates different disabilities, including visual impairments, to help you to make improvements where necessary.