seeing stars
A visual effect intended to imitate Photopsia, a phenomenon in which the retina is stimulated in such a way where an individual may see a flash or flashes of light in their vision. The most common reason for this effect is to portray unconsciousness, or disorientation. Potential causes include head trauma, physical exhaustion, and the use of drugs, or alcohol.
This visual effect is not limited to just stars. The stars can be swapped out for any shape, or symbol – often various types of squeans. Traditionally, cuckoo birds have also been used to represent this effect.