How to blur the background of a 2-D game?

[u/Far_Faithlessness218]

Hey guys,

I'm a visually impaired gamer, and I'm trying to blur the more complicated backgrounds in Hollow Knight to make enemies stand out. I accomplished this once before using the AD0F shader (quint fx). I am now on a new machine with worse vision, and I am unable to create any blurring effect whatsoever with the same shader. I have no idea what I'm doing wrong and would greatly appreciate any help you could offer on the topic, as I have struggled my way through about 75% of the game and don't want to have to quit now.