What Is The Cause Of Severe Headaches And Pain In The Eyes?

Over the past two weeks or so I've been getting really bad headaches. They vary in the time they take to take effect sometimes id be looking at something and all of a sudden it feels like my eyes are going to pop out and my head explode. and other times it feels like the dull throb after being hit really hard but that varies too in its position. sometimes its right behind my eyes, sometimes its just on one side, sometimes its at the back of my head. im sure its probably a lot less serious than I think but i just needed reassuring that its nothing serious.