In LR 5, the image in my second monitor renders blurry as if the photo is out of focus although the image is clear as a bell in the main editing screen. If I click off lens corrections, and then reactivate it, the second monitor window clears up and renders the photo clearly.
This is fixed in Lightroom 5.5, which is now available. (There are several slightly different issues discussed in this thread, so to be specific, what has been fixed is the fact that when a photo is displayed in loupe view on the secondary monitor, it often appears blurry when advancing through photos in the Develop module.) Thanks, Ben