Hi there people at community. I am using OSX BigSur beta, macbook pro retina.
But this porblem started in Catalina version.
The documents appear to be more clear in native Preview app than in DC Reader.
It looks similar to working with or without glasses for those who suffer miopia. Everything is legible, readable, but there is that feeling of a fuzzy vision. I have changed a lot of parameters in preferencies, but nothing seems to work.