The question is not random at all. It is a great one.
(I am going to speak to those without significant DP/DR, but the individuals that have lasting altered perceptual disturbances that at least in the early part of the disorder result in significant distress.)
I started talking on the original forum in 1998. I was less than a year into the disorder, and happy that somehow found a name for it (Thanks to the old HPPD board by Andrew). So, I know there are many who have had HPPD for 40+ years like MadDoc above. I can say that the vast majority of them have adapted to the symptoms, and some of us *cough* may be better off with HPPD having affected out lives vs. death or the other few awful outcomes that accompany substance abuse.
How are the Visual symptoms? Do I still have the same visual symptoms?
Generally, the symptoms do reduce with time. I do take clonazepam, but admittedly I am unable to honestly say if it has caused me more trouble than if I had not started taking it. I think there is a place for benzodiazepines, and a meta-analytical look at posts on this message board could yield an interesting paper or an easily designed research project could shed light on some empirical data on this question. For me, it was the thick static (a severity that I saw figures and cartoons in the spinning pinwheels of the static when I closed my eyes) that prevented me from driving at night and my night vision made looking at the sky impossible and all but the brightest stars and planets would be distinguishable. The purple afterimages at night would take over my vision if I stared off into space. It would be followed by a neon green "veins" in the shape similar or = to Kluver shapes. I can tell you that during times when I did not have access to Klonopin, the anxiety and body feelings are far worse than the visuals, but the visuals are worse as I would expect because in a withdrawal the brain has not had a chance to adapt to the normal receptors.
However, my vision would only be an issue at times it would be for any person with or without HPPD when they would be more aware of their vision (e.g. driving at night on a two-lane road with oncoming lights, staying up too long or looking through a telescope. Excessive glare.) my symptoms have not changed. Truthfully, they are worse, but (NO PANIC) I am certain they are the result of my vision actually getting worse and I need glasses. But, I have been putting off going to get my eyes checked. Iff in one month I haven't made the appointment and can report to anyone about it, please call me out on it. Right now, I have trouble with street signs, reading text close up and my vision was impossible to determine a "number" when I was last tested in 2004 because of the visual issues, and I make sure to take my medication before getting my eyes tested for when driving (and at least I pass these for now).
(I have a lot to say, so I will try and stay on topic the best I can, but you wil get more than you asked as a result.)
Perception of our environment is one of the strangest and most interesting parts of PSYCHOLOGY that I know. I can go a few days without my symptoms becoming a thought that reaches my conscious awareness. So, did I see haloes, walls move, and other visuals during those few days? I would say I saw them just as much as I was consciously aware of the birds chirping around me (they do all the time, but how often do you notice them?) that I had absolutely no real recollection of. We can attend to only so many things, so if I am having sex then I can tell you with 100% certainty that at this point I don't think about HPPD during or after! When I am writing on this message board, I can write for a few hours and talk about the symptoms but not be occupied by my own. However, just as I can now -- I look away at the wall and I see the monitor after image, the wall is moving upwards, everything is still in ghosted vision, Haloes and afterimages follow everything I see -- have these visuals they do not cause me distress. I am more concerned for those who are going to get HPPD and for the individuals who received it only after a few uses and for the people where other disorders interact with the mechanisms of HPPD to make it more difficult to accept that I am my own.
In general, I know people in almost every class of profession and life but notably, none are jet pilots or dentists and also not aware of any of us being a military sniper, and these others where perfect eye-sight is required are doing very well in their lives. When they are not, the cause is usually linked to anxiety and depression that exist with HPPD and experiences of depersonalization or the visuals staying distressful can be an issue without addressing the other disorders. I have ADHD (which is finally getting research to support it as a biological brain disease, so I don't need to validate it but I am 38, have 4 papers in medical journals but live in my family's basement) which is the reason I have been gone so long. I designed the PHP front-end and MySQL backend for the Depersonalization research with Dr. Simeon in a hyperfocused binge and I designed and published research because either I was illicitly taking or finally prescribed Adderall to provide me the ability to complete a task). I also have a "lasting disorder" but it is "cured" which is my right leg's tibia (shin) had a complete spiral fracture and fibula broken like twigs and I almost required amputation, but instead, they used a scalpel to start a 25cm or so cut along my calf and then used surgical scissors and cut through my fascia to prevent compartment syndrome, put a rod through my knee cap down to my ankle and screwed my leg together and I had to wear a wound vacuum 24/7 for 4 or so months until the wound reduced dramatically in size (three times a week I would have the sponge changed by specialists) and then I could get a skin graft to be the fine leg they saved. I was very lucky. However, It causes awful restless leg symptoms (all of the little nerves slowly coming back, and a lot of feeling still doesn't exist on that area of the skin that is a giant scar) and standing for a day will cause me to feel like my knee is locking up, I can't go up and down stairs without using my arms in that case and I have to rest for a day (I can manage the pain if I am not moving, but if it gets too bad I do take tramadol and I will take it to sleep). Before this, I was taking 10-20mg Oxycodone every4-6 hours including when I would suddenly awake as it wore off. Eventually, I asked to step down and I am only telling this story because I am an Addict, and telling your doctor to reduce your narcotics is something I am proud of. However, I am still taking a combination of meds that we were reducing in small steps (until my father was diagnosed with brain cancer and so far we haven't decided it is good to rock the boat) that a substance abuser would consider a dream to have each month: d-Amphetamine, Clonazepam, Tramadol but I can promise my opinion of these are completely different.
Do I still forget my keys and it has been over 2 months and I have yet to get a replacement to my driverse license I lost somewhere? Yes. However, I did keep excellent records and cared for my sick father in a way that I managed his medications, condition where nobody would have said I was inattentive. It is just how my brain attends to things, so like HPPD it is part of my biological situation (but we can learn to adapt and even take advantage of some of the things.
If hearing 1000+ stories from people with HPPD makes me an expert on the topic, then I can tell just from your last sentence tells you already understand our best defense. Humans are generally very resilient and adapt to a lot of weird conditions. I will may not have daily leg pain, but I still have a titanium rod and I wouldn't try competition cycling, and I can't finish a book until I started taking meds so I can function in our world and did I overcome ADHD? I am getting closer, but as my psychiatrist said, "Your brain is special. That is all you will get for my diagnosis on you. I fill out numbers for your insurance."
So, in my opinion, you are going to do fine. Very early on, about 1 year into it I was going to stop looking for my own cure and worrying if it will go away, and it enabled me the freedom to study it and observe it without excessive bias towards seeking a magic bullet cure and be realistic about what the challenge will be. Your only real limit is not landing jets on aircraft carriers at night.