Visual needs

Introduction

Visual impairments can affect people to different degrees, including:

Blind people who are sightless with no light perception.
Those with only slight peripheral vision.
People with light perception but a colour deficiency ('colour blindness').
Temporary impairments such as distraction or glare. ¹

Some people will use a screen magnifier, screen reader and/or Braille display to use technology. Some people may also require travel, mobility and navigational assistance.

Nearly 2 million people in the UK are blind or partially sighted ² . Only one-third of people registered blind or partially sighted are in paid work.

Over one-third (44%) of blind or partially sighted people also have depression, making it the most common secondary condition for those with sight loss ³ .

Examples of visual impairments

The following table lists examples of visual impairments in three columns (permanent, temporary and situational).

Permanent	Temporary	Situational
Blindness	Cataract (cloudy lenses)	Glare
Glaucoma (damaged optic nerve)	Refractive errors (long/short sight, double vision)	Distraction (visual complexity)
Macular degeneration (effecting central part of the retina)

Making things accessible

In addressing some of the design issues below, we make it easier for everyone to use our apps.

Readability and contrast

Use the typographic scale with the font ‘Open Sans’ to create readable content.

Use a colour contrast of at least 4.5:1. Use a colour contrast checker to check.

Design for assistive technology

Use semantic headings and HTML tags to structure the app. Using correct HTML will allow assistive technologies to read an overview of the page when landmarks, regions and headings are implemented appropriately.

Make sure that all elements have correct labels and providealt (or alternative) text when necessary. Good labelling helps all users, such as during issues with downloading parts of the web page.

A linear and logical layout can help users when navigating using a keyboard or when using assistive technologies.

Help convey meanings

Don’t rely on colour only to convey a meaning. Use a combination of labels, icons and shapes to help people identify elements.

References

1. Blindness and vision impairment . World Health Organization . Accessed 5 November 2022. Back to content

2. Blindness and vision loss . NHS . 8 June 2018. Accessed 5 November 2022. Back to content

3. Depression rates are rising among people with sight loss . RNIB . Accessed 5 November 2022. Back to content

Last reviewed 15 November 2022 .