Only seems to happen when using the suros sights SLO-12 and SLO-19. It's been happening for a while so I thought I would share the problem.
-
Its the new bonus lights around your head They introduced it last week. Look in the tower its a virus of bonus. You get it in crucible death by super or picking orbs. Not sure if i see it when i aim for the head But you see it at more and more guardians.