Final answer:
After a subconjunctival hemorrhage resulting from an assault, the first action should be to seek medical attention to rule out more severe injuries and document the assault.
Step-by-step explanation:
The first action to be taken after experiencing a subconjunctival hemorrhage as a result of an assault is to seek medical attention. Although a subconjunctival hemorrhage, where blood collects under the conjunctiva of the eye, may not be severe and often heals on its own, it is essential to ensure there is no further injury to the eye or head. If the hemorrhage is accompanied by increased redness, swelling, pain, or vision changes, it could indicate a more significant injury that requires prompt professional assessment and treatment. Moreover, because the event involved an assault, it's critical both for legal and health reasons to have the assault documented by healthcare professionals and possibly report it to law enforcement.