photon78s Yeah I'm still using the same low 250 nits Innolux panel. Originally I kept it despite the strain because my monochrome red color filter glasses made it usable enough for hours of coding because they seemingly filter out 90% of whatever color technique is causing the problem by making the screen physically a single color to my eyes — and I really lucked out with amazing keyboard build quality/supplier lottery so I wanted to get the benefits of the keyboard ergonomics since all my other laptops have really bad keyboards, with the potential I could improve it with a panel swap later.
But now it's finally usable without the glasses (only within the Linux VM, but that's enough for me because I can run my entire coding environment within there!)
Although I still want to do a panel swap, because overall it's still not the best panel, I wish it could go up to 300 nits since 250 is TOO dim for me and there's something slightly off with the viewing angle where either the left or right half kinda fade to a "slightly blacker tint" if you're not looking at it totally centered (something that is usually fine on other IPS panels. No, this isn't the privacy screen variant, it's just a bad IPS lol.) — plus, I still have a feeling a different panel can improve the Windows side.
But, for now, the panel is at least able to achieve much lower strain inside the VM and not give me reading issues, although it's still a very low quality IPS IMO and has other issues like the brightness and a kind of metallic feeling likely due to the annoying viewing angle situation, outside of strain.
The PWM-like brightness dips don't change in a recording so I'm pretty sure the strain is coming from something to do with both Windows compositor interacting with a feature of this gen of Intel graphics hardware with the end result of a "color sharpening" enhancement being applied. I still seem to feel a similar issue on a native Linux install and even the BIOS screen (where the iGPU is likely already active, because the Lenovo logo prior to it shows at full resolution) but not as bad as Windows. BUT the issue is noticeably reduced by a HUGE amount specifically while the Linux VM is running fullscreen within Windows.
I've recorded the same PWM dips on other completely usable devices like my old Xiaomi Redmi 3 phone so that's not the direct strain source IMO (although the flicker depth is stronger than usual on the T480), the main difference between the PWM "dip" screens and a true PWM-free screen (like the 2016 MacBook Pro I mentioned in another thread) is that my vision in the real world feels slightly less washed out, easier to focus, and colors/contrast look better after using a PWM-free screen, but it mostly doesn't affect my time during using the device itself.
Note that this only applies to the devices with "slight brightness dip every frame"-style PWM, I have worse symptoms directly connected to PWM when it's the more infamous "strobe-like" PWM type.
I still have some optimism that a panel swap could improve the rest of the Windows install though, because different panels may provide different data along the lines of EDID, calibration, or timing info that may cause Windows or the Intel drivers to render to them differently. Or, the way that pixels are arranged or high contrast colors are displayed on different panels may be less likely to create the illusion and strain effect the "sharpening" method is causing. (high contrast colors, not contrast ratio, as this panel has a low contrast ratio but still has the issue)
(I also think either the Intel gen or the panel is connected because I have a Surface Pro 4 with 6th gen Intel HD 520 and a Samsung PLS panel that's running Windows 10 22H2 with very minimal issues and is totally usable for most tasks with the exception of the super bright glossy hiDPI panel not being the best fit for text-heavy stuff like code, compared to newer laptops where 22H2 is totally unusable for me.
Plus, a T480s with an LG 2K panel didn't cause the eye "pain" with the same graphics chip and 1809 version but it did cause some nausea feeling instead plus I did notice similar, but less, abnormal color fringing so possibly that panel interacted with the colors in a different way — had to return that one though I require the panel to work at 1x for a bunch of non-HiDPI compatible apps I use and NoMachine, and 1440p@1x at 14 inches is WAY too small. The LG panel was also one of those panels that shows up as "intense red" instead of a "more relaxing deep orange red" through my color filter glasses, very likely due to use of KSF phosphors, meaning it didn't really "support" my color filter workaround if you get what I mean.)
There is also weird panel lottery cases to still be careful about even when the issue could have more connection to software — I saw two T460 (Skylake CPU) laptops side by side at a used computer store with IDENTICAL AUO panel IDs in Device Manager, both had only the Basic Display Driver running without Intel drivers at all and had the same Windows version, and one was very comfortable to me but the other immediately felt wrong, had a hazy/blurry feeling and a slightly different color tint. That does make me want to find that AUO panel and swap it in though, but when I do that I'll make sure to buy more than one of the same panel because of that experience. Unfortunately that was also only a 250 nits panel though.
BTW, here's an image someone shared surprisingly all the way back in 2013 where an Intel driver updated added forced sharpening artifacts to their ThinkPad screen (an x220 in their case) VERY similar to what I've noticed is present with e.g. the black lines I mentioned within the usual Windows desktop outside of the VM on my T480. https://imgur.com/a/hdvlU
I don't think this type of color processing reached wide-scale use across laptops until several years after 2013, but it's really interesting to see a really early example of something closely resembling the same issue I've noticed. (Note that the cause may be different between laptops, a visually same processing method could be generated for a different reason and by a different source depending on the device. But I just wanted to give an example of what the artifacts roughly look like.)