The posterior segment of the eye, also called the back of the eye, is made up of the retina, optic disc, vitreous body, choroid, and sclera. As a critical part of the visual system, the posterior segment works in conjunction with the anterior segment to transmit and focus light onto the retina. Synonyms for the term can include the ocular posterior segment, posterior chamber, fundus oculi, or simply the back of the eye. Understanding the anatomy and function of the posterior segment is crucial for diagnosing and treating a myriad of eye conditions and diseases that can impact vision and overall eye health.