How disabilities affect website use

Posted by Mark Rogers on Feb 4, 2012 | 


This post  follows on from the one on Disability Statistics, and shows how the most common disabilities affect website use.

Reading difficulties

Reading difficulties and dyslexia are extremely common, and affect 15-20% of US adults. Some groups (such as entrepreneurs) have rates approaching 40%.

This group often finds problems with:

* Note that the high contrast required by WCAG 2 checkpoint 1.4.3 can actually cause problems for people with Scoptic Sensitivity Syndrome, and also some low vision users who need to read the screen very close up (put your face next to your screen for 30 minutes on a very high contrast page to see how unpleasant this feels). 

Color blindness

Color blindness is also very common, and affects around 8% of caucasian males in the US, but only 0.5% of females. Color blindness comes in many varieties with red-green and blue-yellow color blindness the most common, and inability to see any colors (monochromacy) the rarest.

This group often finds problems with:

Dexterity difficulties

Problems using hands and arms affects around 7% of the population, and can make using a mouse hard or impossible. Older people are more likely to have dexterity problems due to the onset of arthritis. Even if users can use a mouse, they'll find it hard to click on small link targets (such as single character links).

This group often finds problems with:

Difficulty hearing

This affects around 4-5% of the population, and becomes more common with age. Relatively few websites use audio, so the majority of sites are unaffected. Many office workers are in the same position, since they have no way of hearing website content at work (speakers are very uncommon in offices, and headphones are frowned upon in some corporate settings). 

This group often finds problems with:

Difficulty seeing

This affects around 3-4% of the population and includes people who are blind and those with low vision who need large print and/or high contrast to read (e.g. people with cataracts or retinal damage caused by diabetes). 

Blind people (and some dyslexics) typically use a screen reader, which read out the words on web page, but reading each word out individually is very time consuming so:

People with low vision:



First posted Feb 2012