It doesn't look blurry to me as well.
I think there are lots of things that can be improved, but I'll probably start improving the overall lighting.
It looks like there are two light sources that are competing to be the main one.
I'll suggest any of the following options (but not all of them, just one at a time):
-Using an HDR image to provide the overall lighting.
or
-Using a Corona Sun + Corona Sky.
From that point, you can move forward to include interior light sources to complement the scene lighting.
Then, you can continue to create and apply materials to your scene objects.
This is just a basic approach and simple suggestions.
Consider reviewing the Corona official Helps desk at:
https://support.corona-renderer.com/hc/en-usI hope this helps.
Let us know the outcome.
Regards.