Because working of free software projects is usually quite decentralised, you may not have a person with sight disability available to help you testing out the usability of the icon.
But you don't need to harm yourself to be able to test what a person with such disability sees ;). A simple blur filter can mimic a typical refractive vision deficiency. Example 1.2 shows a simple script using librsvg's rsvg utility and imagemagick's convert to render a bitmap of your svg icon and apply a gaussian blur on it.
#/bin/bash svgfile=$1 pngfile=`echo $svgfile | sed 's/^\(.*\)\.svg/\1.png/'` pngblurfile=`echo $svgfile | sed 's/^\(.*\)\.svg/\1-blur.png/'` #generate a png rsvg $svgfile $pngfile #blur the png convert -blur 20x4 $pngfile $pngblurfile
Example 1.2. Simple script to generate a simulated projection of an icon as seen by a person with strong vision deficiency.