Is there an option that allows you to sharpen documents?

[werg22]

For documents that are simply scans, or contain images, is there a filter of some sort that sharpens the image(s)? When it's blurry it gets very tiring on the eyes.

[christina]

You can try our Foxit PDF Editor (http://www.foxitsoftware.com/downloads/index.php). With it, there's a build-in Image Editor allows your to modify images.