If you just started a new job, it's likely you also changed your work layout. Ergonomics can make a big difference. In my case, I eventually figured out that I

If you just started a new job, it's likely you also changed your work layout. Ergonomics can make a big difference. In my case, I eventually figured out that I need my desk at a specific height. Being even an inch off causes burning and tingling in my arms after a couple days. So every time I move offices, step 1 is adjusting the desk height. On the eye strain, have you switched monitor brands or OSes with your new job? Small things like color temperature or type of LCD subpixel rendering can take a while to get used to. One configuration isn't inherently better than another; it's just novel and different, and your eyes might be doing a little extra work recognizing slightly different glyphs on the screen. If this is the cause, then the discomfort should go away soon.