When you visit a website and find something that you want to read, or you receive an email or an E-newsletter, that you want to read on the screen, select the text (Control +A), copy it to the clipboard (Control + C), open the word-processing programme and paste in the text (Control + V).
Select the text again (Control + A) and then select a larger size font from the menu. (This will help you to see the text better and make it easier to read). Save the file. (I usually choose a name like junk and then continually overwrite this file as needed).
Read the file and then when you are finished with it, delete the file. Some people have probably thought of this already. I am writing this for the people who did not think of it yet!
Also if you are composing an email or an article on the computer, do it first in a word processing program in a large text size. Then you will be able to see your text better and find your mistakes.