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Designing for the Visually-Impaired

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Blindness

Blindness is the condition of lacking visual perception due to physiological or neurological factors.

Blind Users:

  • Do not use a mouse, use keyboard
  • May use a screen reader to listen to the content (JAWS, FireVox)
  • May use a refreshable Braille display

Accessible Design Techniques:

  • Provide text description for all images & photos ("ALT" attribute)
  • Use meaningful link-naming convention - 'See Training schedule' rather than 'click here' for Training Schedule
  • Use proper HTML Markup (h1-h6 header tags, etc.)
  • Avoid scripts that require mouse usage

Low-Vision

While low-vision users may not be blind and will not use screen-readers to read content, this group makes up a large part of the workforce and the general population. Certain factors such as age and health contribute to low vision. Learn about the common causes of low-vision.

Low-Vision Users:

  • Use Screen-Magnification Software (ZoomText, MAGic)
  • May resize text via Browser/System Settings

Accessible Design Techniques:

  • Limit or eliminate text within graphics
  • Have plenty of contrast
  • Use relative rather than absolute font sizes

Color-Blind

Another form of visual impairment is Color Blindness. Color Blindness a color vision deficiency in humans, and is the inability to perceive differences between some of the colors that other people can distinguish. It is most often of genetic nature, but may also occur because of eye, nerve, or brain damage, or due to exposure to certain chemicals.

Color Blindness:

  • Affects 7-10% of the male population
  • Affects 0.5% of the female population
  • Reds & greens are often indistinguishable

Accessible Design Techniques:

  • Do not rely on color alone to denote information
  • Foreground (text) and background colors must provide enough contrast to allow color blind users with or those using a monochrome screen to view information
  • Use additional cues or information to convey content

Resources:

To determine whether your images or pages are accessible to color blind persons, test your content with VizCheck

Return to 'How Do I Design for Accessibility?' page

Last updated: 6/12/2014 4:09:57 PM