Macbook air mid-2011 visual glitch problem
Based on our discussion and some fact finding above:

I would say your hardware is fine /the Intel HD3000, but it could be on its way out!, means it could be dying the slow death.

You can double check and run a stress test for the GPU using this little program, or look for your OSX version.

GpuTest 0.6.1 is a bugfix release for Mac OS X only. The CSV file (for benchmark scores) was no longer generated at the end of a benchmark. This CSV file is stored in the root folder of the current user (_geeks3d_gputest_scores.csv).





However, I still think you have a software (programs) interference issue.
Remember the Intel GPU uses shared memory, so that could lead to a problem you are having.

Finding out which program is interfering could be tricky, but you had to just turn them completely off one at the time.

In your case I recommend:

Use an external monitor (or LCD Television) to:

1-see if it is a problem with the build in display

2a problem with the flat band cable to the build in display

3-actual problem with the GPU chip