How long does a bloodshot eye take to heal. And does it heal naturally

Hi there "bloodshot eye" or subconjunctival hemorrhage can have several possible causes. You would need a review with a clinician to determine this, although if there is no underlying condition it would typically heal within 2 weeks.  Read more about them at this link:

Subconjunctival hemorrhage (broken blood vessel in eye) - Symptoms & causes - Mayo Clinic