PDF files are great for printing but they can be really difficult to use if you want them read out to you or you want to change the colours and fonts used.
People who have low vision or dyslexia find it easier to work with text when it is spoken aloud or has different colours or contrast. Accessible PDF is a free program from Claro Software that lets you read PDFs with the colours and fonts you want and makes it easy to read the text aloud with other programs such as ClaroRead. You can zoom
in and out, use high- or low-contrast colours, and save your PDF as text or a web page for future use. You can even follow internal contents links to let you navigate the document.
Click this link to download Accessible PDF Reader from Claro.