WCAG 2.1 – Low Vision

On June 5, 2018, WCAG 2.1 became the official W3C recommendation. Previous versions were released in 1999 (WCAG 1.0) and 2008 (WCAG 2.0). All new updates build on WCAG 2.0 instead of replacing information (also known as “backward compatibility”). WCAG 2.1 includes one new guideline and 17 new success criteria. Eight of these criteria focus on improving mobile device accessibility, five on the low vision user and four on cognitively impaired user access. If your organization has user accessibility concerns, WCAG 2.1 at Level AA is our current recommendation. The five criteria addressing users with low vision – including reflow, non-text contrast, text spacing, content on hover or focus, and status messages – are reviewed below.

Low Vision

Make it easier for users to see and hear content including separating foreground from background.

Distinguishable 1.4

1.4.10 Reflow – Level AA

Content can be presented without loss of information or functionality, and without requiring scrolling in two dimensions for:

  • Vertical scrolling content at a width equivalent to 320 CSS pixels
  • Horizontal scrolling content at a height equivalent to 256 CSS pixels
  • Except for parts of the content which require two-dimensional layout for usage or meaning

1.4.11 Non-text contrast – Level AA

The visual presentation of the following have a contrast ratio of at least 3:1 against adjacent color(s):

  • User Interface Components: Visual information required to identify user interface components and states, except for inactive components or where the appearance of the component is determined by the user agent and not modified by the author
  • Graphical Objects: Parts of graphics required to understand the content, except when a particular presentation of graphics is essential to the information being conveyed

1.4.12 Text Spacing – Level AA

In content implemented using markup languages that support the following text style properties, no loss of content or functionality occurs by setting all of the following and by changing no other style property:

  • Line height (line spacing) to at least 1.5 times the font size
  • Spacing following paragraphs to at least 2 times the font size
  • Letter spacing (tracking) to at least .12 times the font size
  • Word spacing to at least .16 times the font size

1.4.13 Content on Hover or Focus – Level AA

Where receiving and then removing pointer hover or keyboard, focus triggers additional content to become visible and then hidden, the following are true:

  • Dismissible: A mechanism is available to dismiss the additional content without moving pointer hover or keyboard focus, unless the additional content communicates as input error or does not obscure or replace other content
  • Hoverable: If pointer hover can trigger the additional content, then the pointer can be moved over the additional content without the additional content disappearing
  • Persistent: The additional content remains visible until the hover or focus trigger is removed, the user dismisses it, or its information is no longer valid

Compatible 4.1

4.1.3 Status Messages – Level AA

In content implemented using markup languages, status messages can be programmatically determined through role or properties such that they can be presented to the user by assistive technologies without receiving focus