If you are experiencing flickering on the screen when connecting through Citrix, it may be related to DPI scaling setting on your computer (particularly if you have multiple monitors). Please try the steps below to resolve the problem:
1. Go to Program Files (x86) > Citrix > ICA Client.
2. Right-click on "wfcrun32.exe" and select "Properties."
3. Go to the "Compatibility" tab and check the box next to "Disable DPI scaling on high DPI settings."
4. Click "Okay" to save the changes.
5. Repeat steps 2-4 for "wfica32.exe"
Additional information: http://discussions.citrix.com/topic/349273-problems-with-windows-8-and-dualscreen/