why the fonts in word 2013 are blurry?

Dont try to cover your errors Mr Robbins. And try to be smart. I think you should change your computers to new ones, with a large screen. Im having a 27inch Lenovo A730 and as you say if there's something wrong with the PC you should blame Lenovo. What can you tell me if i tell you this? I open the same word file in this same PC with Office 2013 and Office 2010 and if there's a massive difference in the font clarity. if you cant see it then that should be due to your age.... and sight problem in which case you have to change your EYES instead of my PC's graphic card......

Open these files separately, enlarge and see the difference.....

Word 2010 image;

Office 2013

If the text can be 'sharp' when you are in the footer why can't it remain so when you are working on the main page?

I'm willing to bet that if MS development was to reply to this question they would call the issue you identified, "clear text in footer", as a "defect" or BUG.  If Word was working as they planned it to, EVERYTHING would be blurry!  Apparently, for some reason the footer is not using the "right" / new graphic display system.

Now that you have identified the "problem", it is probably on their "to-do" list to "fix" (what the rest of the world would call BREAK) it.   Just be glad that it is likely a very low priority, does not affect many people.

Sacha's fix is the best. UPGRADE back to 2010 or earlier and

DEMAND a **$$$**REFUND $$$ 

for the defective product, Office 2013!