High Contrast Proof CSS Sprites
CSS sprites are a useful method to display graphics while preserving bandwith and improving page rendering times. One of the problems with CSS sprites when it comes to their accessibility is that some operating system display themes such as Windows High Contrast mode have the effect of hiding CSS background images. So if an alternative version of the image is to be displayed when a user changes the default theme to suit their requirements, the developer has needed to provide an alternative with images inserted inline rather than as CSS background images. In many cases the developer does not do this, as it is a lot of extra work and undermines the performance benefits of CSS sprites.