Editing is intensive work. It takes a level of concentration that a normal human being can sustain only for a limited time. An editor can go a little beyond that time, but still, we all come to a point where we just can’t think anymore.
In my case, though, my eyes often give out before my brain does. Sometimes, with my tired, scratchy eyes, I see things that aren’t there. For example, not too many weeks ago, I copyedited a book by someone who was once in a rock band. I was editing along late one afternoon when I came across a sentence very similar to this:
We giggled for the rest of the year.
“Gee,” thought I, “that’s a long time to giggle. There might have been marijuana, but still….” Then I blinked my eyes hard, zoomed in from 180 to 200 percent, and… Oh, gigged. They gigged for the rest of the year. Well, that made sense, for a rock band.
It was time to step away from the manuscript. I’d edited for a good five hours, and that’s my limit. If I do more, I start seeing giggles everywhere.