What Causes Broken Blood Vessel Under The Eyes?

I suddenly have what appears to be a broken blood vessel on the lower bag part of my skin under my eye. I did not injur or stress myself. It jestcseemedcto be sore when I itched my eye and then I noticed it a few hours later. It is dark red in color and about the suze of a dime. Starting near the corner of my eye and going down. Should i be worried? It is not painful to the point of feeling similar to a bruise to the touch and no change in vision.