How far apart should my tomato plants be from corn?

In the book "Carrots Love Tomatoes" it says "Don't plant tomatoes near corn because the tomato and corn earworm are identical."

My question is . . .

1. How far apart should they be? A few feet? Several yards? Not in the same yard? Next county over?

Mine have been fairly close together in the past (just a few feet) because I have planted in raised beds. Have had both tomato horn worms and corn ear-worms on my plants. I have to say, they do not look "identical" to me so I'm not sure what they are talking about. I took the tomato worms off the tomato plants and squished them, but not nearly successful with the corn earworms.... don't know if that helps, but just thought I'd add my two cents worth.