Adobe Acrobat X Document Resolution/Clarity Issue

Hello,

I have Adobe Acrobat X (Version 10.1.16) software on my computer.  If I open a pdf file on a website, I see the document in what I consider to be good resolution (upper text in image).  If I download the document that is open in my web browser on my computer, then exit the internet and open the downloaded document, I see the document in what I consider to be poor resolution (lower text in image).  I've inserted an image showing what I mean.  How do I get better quality when I open a pdf file I've downloaded?  Thanks for your help.