I had HPPD for a minute when I was 19. I haven't replicated, but I went really hard into DHA enriched soy milk for a while. I don't know if there's anything there to really connect it, but my symptoms resolved. Phytoestrogens may have done something, and the DHA may have done something, perhaps a combination, or maybe the AA profile of the milk... Or maybe it was just rebound capacity thanks to my young age (admittedly the most probable explanation). This is despite continuing drug use.

I also did a lot of meditation, and pretty extensive sessions (40-60m) of it for a few months.

Some things to consider if you're interested.

I've taken DHA enriched soy milk, so unfortunately that didn't help. Based on the link I posted, there's two types of HPPD. Type 1 is temporary and recovers, type 2 is chronic. I have type 2. I haven't tried any of the prescription meds though as most doctors are unfamiliar with this condition and the one neuro-ophthalmologist (who was hands down the best doc ever) I saw is no longer in practice sadly.

I think HPPD is going to get a lot more attention as psychedelics continue to grow in mainstream popularity. The significance of HPPD as a potential long-lasting side effect of psychedelic use has been downplayed a lot in the past, but I've been seeing more uptake of the topic in mainstream discussions.

Andrew Callaghan of "ALL GAS NO BRAKES" suffers from HPPD and has started to discuss it openly: https://www.youtube.com/watch?v=zUbod5t_2oM&t=1247s

I think hearing HPPD stories from popular media figures like Callaghan can help seed healthy discussions about the risks of psychedelic use. In the past few years, the media has been way too optimistic about the potential positives of psychedelics while almost ignoring the risks and downsides.

I've had HPPD symptoms for many years after my first trip, and all of them are beginning to disappear now that I finally properly continued trauma therapies (with no substances involved).

I'm just making this up, and have zero studies to quote, but may it be that HPPD is actually a positive sign, on a path to healed trauma?

I think these are normal features of our perception and most people are just used to experiencing them to the point where they are filtered out at baseline level of consciousness.

Have taken shrooms thrice, 16 years ago, and got HPPD right from the first time. Still have the visual snow, increased palinopsia, and "coloured dots" that last about 1 second, from time to time (those have decreased exponentially over the years). It's not really annoying at all in the end but obviously the visual system didn't recover. At the time the sun was thrice the size for me. Would have been great to have only those symptoms...

I'm not sure if it's HPPD but if I stare at anything with a pattern (tile, carpet, etc) it kinda starts to move/bleed together, kinda like a river or paint. I think I first noticed it after doing psychedelics in my late teens but it has persisted since.

That doesn't sound like it, I've had that since I have memories and I didn't do any psychedelics as a baby and my parents nor my grandparents never touched any of the stuff. Visual artifacts like that are normal for some parts of the population.

I think you need to worry if you're getting into depersonalization-derealization, otherwise you might just have some minor visual artifacts.