Chosen Solution
I just purchased a 2018 15" MacBook Pro and when I plug in my external monitor, the text has this shadow which makes it hard to view for long periods of time. I have a 2017 MacBook Pro and it has no issues. I tried 3 different monitors and mDP and DP and still the same results. Anyone else have this issue? See the screenshot below.
Update (08/20/2018) here you go. I used Excel. Same issue but easier to see.
The screen shot won’t show the effect as it goes directly to file vs what you see on the screen. You’ll need to take a camera to take the picture of the screen. Do make sure you have no glare on the display by your background and have enough light the camera takes a good image. If you can do a side by side with the same file that might help. Are you using an Apple cable (displayPort or Thunderbolt)? Or are you using someone else’s? Also who’s adapter are you using?