Mavericks, Line on the left edge in login screen

I noticed a line on the left edge in login screen on my Macbook Pro, first I thought that it was a screen problem, but then I realized that I have same line on Macbook Air and iMac too. And I can take a screenshot of the line.

It appears only in login screen, on left edge of the screen. After I login screen looks perfect. It looks like dark shadow that covers wallpapers is drawing wrong.

Does anyone experience same issue?

Michaelgtrusa said:

This seems like an issue with your GPU.

Click to expand...

It shows on all of my macs (Pro, Air, iMac), but only on login screen.
So, this obviously rules out GPUs and leaves me with some software or peripherals issue