Problem with screen

I was in a meeting of work and out of noware a blue/green line poped up in my screem and the bottom half started flickering. I did not do anything crazy with my laptop, did not even drop it once so for me it is weird that this has happend. I always carry my laptop in a protective case and never bumped it into something, dropped it or did anything that could cause this problem.

I want to know why this is happening and if this is a normal issue?

Also, does it goes away or is my screen broken now?

Hope to hear from you.