An Open Source vector graphics editor, with capabilities similar to Illustrator, CorelDraw, or Xara X, using the W3C standard Scalable Vector Graphics (SVG) file format.
This is a personal story of someone suffering from glaucoma (Primary, Open-Angle Glaucoma) who has first-hand experience of visual field defects. This article explains what glaucoma is and how to design elements for websites, such as layout and screen resolution, to aid the comfort of reading.
Complex but possible useful for background reading.
"Web Content Accessibility Guidelines (WCAG) 2.0 covers a wide range of recommendations for making Web content more accessible. Following these guidelines will make content accessible to a wider range of people with disabilities, including blindness and low vision, deafness and hearing loss, learning disabilities, cognitive limitations, limited movement, speech disabilities, photosensitivity and combinations of these. Following these guidelines will also often make your Web content more usable to users in general. "