Screen blanking/flashing

I've been using my new MacBook Pro 15" (2015) running Yosemite (10.5) for the last couple of months with no problems, however in the last couple of days I've noticed distinct screen blanking/flashes on four occasions (that I'm aware of).

The screen just switches off and reloads instantaneously. This takes no longer than a second.

I am just browsing the web in and streaming music from Safari. It normally happens when a webpage is loading.

Any ideas as to what this is?

Thanks!