Not too long ago, Apple updated its 27-inch iMac to what could possibly be the last ever Intel-based iMac. It is a powerful computer with an upgraded webcam, but unfortunately for some users, it seems that they are experiencing graphical glitches when they are using their computers.
For now, it seems that this mostly affects users who own the 27-inch iMac configured with the AMD Radeon Pro 5700 XT GPU. According to a MacRumors reader torifile, they posted on the forums saying, “Last night I thought I saw, out of the corner of my eye, a horizontal white line flash mid-way up the screen. It was really fleeting and I thought I was just seeing things. This morning, I saw the same thing. The computer isn’t running hot or anything.”
It is unclear if this is a hardware or software based issue, where if it is the latter, then it could be rather troublesome to get it fixed, but if it is the latter, hopefully updates to macOS or to the drivers of the GPU might be able to solve the problem. In the meantime, some users claim to have fixed the problem somewhat temporarily by opting to use a scaled resolution instead of using the default resolution, but like we said, it is temporary and not really an ideal fix.
Hopefully Apple will have a more permanent fix for the issue soon. In the meantime, you can check out the glitch in action in the video above.