Screen issue with OS X Yosemite upgrade

[Millo]

Hi,

After upgrading to Yosemite, I have noticed that occasionally the screen will pixelate. See pictures below. Any ideas why/how

to fix?

I am running a MacBook Pro (Retina 15-inch, late 2013)
2.3 Ghz Core i7
16GB 1600 MHz DDR3
Intel Iris Pro 1536 MB

Thanks

Issue:

Should look like:

 

[oldscribe]

Hi and welcome,

Have you completely shut down Mac left for a minuet then rebooted?

 

[Millo]

Hi,

Yes. It happens periodically. It always rectifies, but has happened several times.

Thanks,