> I've had strange eye problems that my doctor hasn't been able to explain, and I feel like my cognition is declining
You could also explain this with low-level heavy metal exposure, e.g. mercury, as well as a large amount of other possibilities :-)
I thought hard if I should write this, as a joke and only the above line at first, but here it goes. Having read your second paragraph too, that is pretty much exactly what I said to myself a decade ago and before. Then some things escalated a little bit and I was forced to either accept all my increasing issues, or do some research myself.
Turned out I had chronic heavy metal poisoning from mercury. Fortunately diagnosis was made easy because I actually had high levels of it in hair and blood (and urine - same as blood since that's where that comes from). Anyway, the scale of the problem was only made clear during chelation therapy, when both I as well as my (university clinic researcher) doctor were amazed at all the things that improved, including "miracles" such as thyroid normalization (had been enlarged and with a nodule for decades, completely gone within half a year of DMPS chelation, left the endocrinologist speechless, literally, he checked me twice with ultrasound to make sure he had not make a mistake). This issue is next to impossible to diagnose with today's methods, unlike acute poisoning, because how much you see in blood, urine or even hair does not say anything about the size of the problem, it only shows up when it actually moves around the body which it only does after exposure.
I had had dry eyes too, and of course the ophthalmologist as well as I myself attributed it to too much screen work. Today, after years of chelation, I sit in front of a monitor much more than ever before - but now I have zero issues. Same with RSI. Sooo many little things are completely gone from my body, depression too.
The crazy thing is, up to that point ~10 years ago when I had to confront that something was not quite right, I called myself "healthy". And why not? I could run a half marathon just for fun and still come back feeling relaxed. All the many little issues I had, such as a few warts on the feet (more and more over the decades but I ignored the trend), winter depression (many people have that, it's normal!), eye problems (not really severe, so not worth thinking about it) and many many other, my brain refused to think about it. The reality my brain created of my world was highly distorted, but I did not know it. Only the huge and unexpected changes happening after I began chelation (DMPS, later DMSA) showed me the extend of the thus far ignored problem.
Beginning the story indirectly, when I began the treatment I was not even close to being sure about it all. The only reason I had even tested for mercury was because I was desperate, there just was no other option left, after consulting many doctors finding nothing. After having been given PPIs for the problems that had forced me to start looking in the first place my issues exploded in severity: I had never felt so bad in my life. With barely any stomach acid from the PPIs - I could hardly digest anything, it would lie in my stomach for way too long - I had reflux near constantly. Each time I lay down to sleep, really every single time. With much reduced stomach acid, which seemed to have a very strong opposite effect of what it was intended to do. I also had incredible bloating and my mouth felt funny. The professor gastroenterologist treating me thought it was just nerves.
The first thing I found was, after having first dismissed it as esoterics when I found it on the net, that I had a candida problem. Proven by the significant immediate effect of taking Nystatine (anti-fungal) and a doctor confirmed it. Later I even got Fluconazole, an internal antifungal, again with huge effects. Just an aside, funnily enough, the warts on the sole of my feet that every doctor would say were caused by a virus disappeared by 95% after Fluconazole.
Anyway, I learned Candida never is a cause but itself just a symptom, and since I had none of the conditions that are listed in the text books that might cause it I had to continue looking. Heavy metal poisoning was one of the only options that would explain the Candida, but also everything else. And I had only one possible source: amalgam fillings.
When the tests confirmed high levels of mercury in my hair as well as in my urine I still was not completely sure: It was high but not high enough to explain the severity of my issues. The doctor I went to said it was high enough to justify starting chelation, but I must have something else. I had the remaining three fillings removed with special equipment and protection. I had had three or four removed decades earlier without protection, just normal drilling, at the beginning of my CS study, and now something made sense: At the time I had suddenly, out of nowhere and pretty much overnight, developed almost-asthma level pollen allergy, and for half a year I had severe problems with the right leg joint. I never went to a doctor for the joint because the symptoms clearly showed me it was not "physical", I can't explain it with a few words. I also developed severe insomnia and - as I understand now but not at the time - "dumb". I had always been good at math, for example, but suddenly it was a problem. Stuff that today, after all my chelation, again looks very easy to me. I still passed and I was still very good at everything more practical so getting through the study was no problem. At the time I completely ignored all those sudden issues and took it as "that's just live".
Everything started to improve greatly during the first year of chelation, and after the fifth or so DMPS treatment in the following weeks the tissue around my right-side thyroid became very active. That was very curious, because I had had a double-sized right thyroid with a nodule for at least two decades, re-diagnosed just a year prior. Recommendation back then was surgery to get rid of the nodule. The tissues in that area became active after two or three DMPS treatments. I went to the endocrinologist again when I felt nothing else there. He did an ultrasound, and when he was done he started casually looking through his notes and became more and more agitated. He asked me to lie down again and he repeated the ultrasound, right side only this time. At the end the result still was this: Thyroid size nearly completely normal, and the nodule had disappeared completely. That was the point when I actually believed that yes, I had found the source of the problem.
Regarding an even more clear proof for amalgam fillings as the cause:
After about a year the doctor wanted to make an injection in to my buccal mucosa. It's just mucosa, so you don't need any force, but his needle ended up deep inside jaw bone. He found several places where the needle easily penetrated into bone. All those places where where amalgam fillings had been for two or three decades. He injected DMPS and just like in the thyroid area the are began to "work". Very actively. A year later the needle could not penetrate anywhere any more. The jaw remained a very very active area though for years, and it still reacted to chelation.
An aside: The are had been OPG x-rayed a few times in the years before because I had finally gotten my crooked teeth fixed and jaw extension surgery too (now I have perfect bite and teeth, wonderful!!!). No doctor ever saw anything in my jaw. One wasn't sure about seeing a tiny shadow near one root - the one where I had the most issues and that was the most active later during chelation - but didn't take it serious enough and didn't follow up (when patients don't complain why would you if it's so subtle). But bone that can be penetrated by a needle easily is very broken. This shows how much (more) broken something has to be to show up even in an OPG x-ray.
My doctor never found anything else and now he too thinks that the only problem there ever was were the amalgam fillings. A lot - a lot! - of very interesting stuff happened to me, the chelators only paved the way out and started it, 99% of the actual work was done by my body (most chelators only work in extracellular space anyway). For example, there were three months of nightly 3-4 am kidney pain, but after the nephrologist found that despite elevated protein levels in urine there was no sign of kidney disease I didn't worry about it. It fit into the pattern of stuff happening at various times all over my body and my brain, a new phase starting every few months in another area of the body. For those three kidney pain months I simply got up when it started at 3 am or so, went to bed when it stopped at 5 am and slept until 10 and still got my sleep. No problem.
Even tough I'm a CS person, I actually have a background not in medicine, but (for fun and out of interest) I've also have many courses in biology, chemistry, org.chemistry, biochemistry, anatomy, physiology, neuroscience, several courses in each. I don't care about pathologies, I only wanted to understand the basics of biology and life and of human physiology.
You could also explain this with low-level heavy metal exposure, e.g. mercury, as well as a large amount of other possibilities :-)
I thought hard if I should write this, as a joke and only the above line at first, but here it goes. Having read your second paragraph too, that is pretty much exactly what I said to myself a decade ago and before. Then some things escalated a little bit and I was forced to either accept all my increasing issues, or do some research myself.
Turned out I had chronic heavy metal poisoning from mercury. Fortunately diagnosis was made easy because I actually had high levels of it in hair and blood (and urine - same as blood since that's where that comes from). Anyway, the scale of the problem was only made clear during chelation therapy, when both I as well as my (university clinic researcher) doctor were amazed at all the things that improved, including "miracles" such as thyroid normalization (had been enlarged and with a nodule for decades, completely gone within half a year of DMPS chelation, left the endocrinologist speechless, literally, he checked me twice with ultrasound to make sure he had not make a mistake). This issue is next to impossible to diagnose with today's methods, unlike acute poisoning, because how much you see in blood, urine or even hair does not say anything about the size of the problem, it only shows up when it actually moves around the body which it only does after exposure.
I had had dry eyes too, and of course the ophthalmologist as well as I myself attributed it to too much screen work. Today, after years of chelation, I sit in front of a monitor much more than ever before - but now I have zero issues. Same with RSI. Sooo many little things are completely gone from my body, depression too.
The crazy thing is, up to that point ~10 years ago when I had to confront that something was not quite right, I called myself "healthy". And why not? I could run a half marathon just for fun and still come back feeling relaxed. All the many little issues I had, such as a few warts on the feet (more and more over the decades but I ignored the trend), winter depression (many people have that, it's normal!), eye problems (not really severe, so not worth thinking about it) and many many other, my brain refused to think about it. The reality my brain created of my world was highly distorted, but I did not know it. Only the huge and unexpected changes happening after I began chelation (DMPS, later DMSA) showed me the extend of the thus far ignored problem.