Technology which can help people with disabilities use the web
Touchscreens are a common place assistive devices for user with ID.
Touchscreens are common due to their immediacy compared to a standard mouse, which requires complex correction of control movement abstracted from the focus of interaction.
Some operations, such as drag-and-drop, may also present a significant challenge to users with ID, even if modified pointing devices are available.
While essentially just emulating a standard mouse and requiring no major technical adaptations, touchscreens have a few implications which developers and designers should account for.
Touchscreen users often use low screen resolutions such as 640x or 800x to increase the size and accessibility of clickable areas and prevent mistaken clicks.
Pages which do not render fully in smaller viewports and require use of scrollbars will present barriers.
Lower viewport widths should be supported without horizontal scrolling and in-page navigation using anchors employed to mitigate requirements to interact with vertical scrollbars or a keyboard.
Button, icon, hotspot sizes
Since the hand and finger can often obscure the display during interaction, use of very small buttons, icons and links in close proximity should be avoided.
Mouse button and click behaviour
In many circumstances, actions should be mapped to mouse button press rather than release events.
For example, in Flash using the onPress rather than the default onRelease event handler will most often be required for time critical operations such as within games.