I'll be honest and say I really have not tried this yet. However I will also stick with this and say the option needs to remain for Off, period end of story. Though to be honest, I wish you'd just make post processing a 'group' setting for generic quick picks, then put a fold out that lets people control all of EACH thing on a more granular scale.
I've played this game, sometimes heavier than others ya know, stuff happens, but I've been here off and on since first day and I preordered. I know we're all getting older, but, I've in the last couple years started to have some games straining my eyes sometimes. This does not happen all the time, and typically it's a certain game, or an effect in, said game. In Warframe for example, I disable motion blurs, many distortions, some reflections, possibly it's color grading too I forget, think they have another name for it if it's what I think it is.
But one thing I will say is I have not played a ton, since EOD, I hadn't had the money for it yet, and I picked it up on the sale, and I also came recently for the LS1 replay and getting the classic LA teleport item which is neat. I was very psyched that DX11 had come out too since it'd taken so long, and I mostly wanted the fps bump, that still stands and I don't want to lose it, I know it could improve/alter some of the other graphics stuff as well. Thing is I don't know what, precisely, and it changes on every game depending on how they do it, of course.
But, I played all of LS1's stuff through in the new remaster, got the teleport thing, got EOD on the black friday sale and started it, and have since finished story, so I've been playing off and on another for I dunno 4-8 weeks probably? And in the last week or so, my eyes have been AWFUL. I don't know what happened, but the eye strain's been off the charts and I know it's coming from GW2, none of my other games are triggering it, and with GW2 I can feel a lot of strain instantly drop when I shut off post processing (or did before this patch I have not tested the new one yet) something is going on with that post processing, I love making things look good, but sometimes not everyone's eyes can tolerate it all, and in this case, I hate to shut off every single post processing type option just to target one thing, so I really, really, hope you consider putting in more granular controls for post processing, I for one would really like to figure out more of what in the PP settings is stressing my eyes so much. I would hate to stop playing this especially so shortly after finally getting EOD too but the strain is no joke.
In any case I don't think even shutting that off removed all of that eye strain either, I'm not sure what's causing it.