Don't see how he can see sub pixels so it's likely an OCD thing, where he thinks he can see them which annoys him, so most like!y yes!
Guys, what I'm trying to say is... Say your candlestick body is 5 pixels wide. Then on an LCD monitor it would look like ||| ||| ||| ||| ||| (||| = 1 RGB pixel). That looks really terrible like the chart is too perfect. If you focus for a long time on the chart, your eyes can't/doesn't like it. On a CRT monitor, the 5-pixel wide candlestick body would look like ... ... ... ... ... (this is much easier on the eyes). To simulate the CRT monitor effect, we would need to do something like anti-aliasing. But the only built-in image processing effects in C# are bicubic and bilinear image resizing... Like if you stretch ||| ||| ||| ||| ||| by a bit using bicubic/bilinear algos, the resulting candlesticks look a bit softer. Like making a jet engine's single crystal turbofan blade, there's an art/science to it or the blade won't last very long. So, the question is what is the optimal method/values to process the raw image on an LCD screen...?
You can't change the monitors Dot pattern with code, it's hardware. Sit further away ? Anti Clare screen a cloudy light grey to soften the image. Just stop looking for closely I guess.
If you're working in code you could certainly set up an algorithm that finds the edge of any straight line and then randomly removes pixels from that line to blur it. Here's a quick link of a topic on StackExchange on the subject (https://stackoverflow.com/questions/58926559/blurring-an-image-with-c). As someone who both once maintained aircraft with single crystal power turbine blades and who currently runs a software company, I can tell you this is by far the easier problem to solve! That said, the issue is that, while I don't doubt it looks really terrible to you and your eyes don't like it, that perception is probably somewhat unique to you. So you're gonna have to do the work to code it to your liking yourself, there's little chance that someone else would have done it because it's not something most of the rest of the world seems to see as an issue.
It seems like your eyes are very unique / special / different. Try looking out for the CRT monitors. You might be able to buy some old CRT monitors. Humans have made great progress by replacing the crt with lcd monitors. the resolution, the image quality have improved massively. people used to have headaches looking at crt monitors. now the headache is virtually gone.
Hated the flicker much less headaches barely code aswell I guess Had 2 x 17inch crts might of been 19inch on on my desk huge heavy, massive bezels took up to much space, got 2 x 24imch and a gaming PC with space left over. Atleast Cats didn't send CRTs flying, duct taped the LCDs to the wall