The abbreviation PDF stands for Portable Document Format, and this file format offers many benefits for creating, sending and presenting regular documents. However, these some run-of-the-mill PDF documents can look blurry based on a few factors. The original paper-document had poor print quality during scanning.The person who edited the PDF used a poor choice of fonts in the digital document. As the end user, you can't go back and control the creation of the PDF. However, if you have Microsoft Windows, you can use functions in the operating system to possibly enhance the PDF as it appears on the screen.
Click the circular Windows orb logo in the bottom-left corner of the desktop (also known as the "Start" button). Type "Adjust Screen Resolution" in the search box at the bottom of the Start menu. Press "Enter" to open the Screen Resolution page of the Display settings window.
Open the drop-down menu next to "Resolution." Move the slider all the way up to the setting that is labelled as "Recommended" by the Windows operating system.
Click the "Apply" and "OK" buttons to set the computer monitor to its native resolution, which might help to fix blurry text in the PDF document as it appears on the screen.
Type "DPI" in the search box at the bottom of the Start menu. Press "Enter" to open the Display settings window.
Click "Set Custom Text Size (DPI)" in the left pane of the window, which opens a new dialogue box.
Check mark the box next to the following option in the Custom DPI Setting dialogue box: "Use Windows XP Style DPI Scaling."
Click the "OK" button to have Windows 7 use Windows XP DPI scaling, potentially reducing the incidence of blur in the PDF document.
Check your printer's ink levels to rule it out as the reason for blurry text on printed paper before scanning. The Windows 7 operating system is capable of reading printer ink levels, without the need for the manufacturer's proprietary software. Make sure the ClearType and TrueType functions are enabled in the computer's operating system.