You might check out BeeLine Reader (I am the creator). [1] It's fairly popular in the ADHD community because it enhances visual focus while you're reading. Some people are able to read for 2x-10x as long with BeeLine versus without. I'm always happy to help out HNers with a free code for our browser plugin, just shoot me an email (contact in profile).
1: http://www.beelinereader.com