File comparison

Ken Springer wrote:

As time goes by, it gets harder and harder for me to see those mistakes.
By "see", I actually mean *see* the mistake. For instance, if the word
"saved" is in the text, and the font and size of the text is the right
physical size, when I focus my eyes on the "v", I do not see the
trailing "ed". :-(

No matter how many times you may proof your own writing, your eyes
(brain) tend to see what you expect to see. You know what you meant to
write, so that's what you tend to see. Many posters never review what
they wrote before hitting the Send button.