Enophthalmos can be defined as a relative, posterior displacement of a normal-sized globe in relation to the bony orbital margin. Non-traumatic enophthalmos has a wide variety of clinical presentations and may be the first manifestation of a number of local or systemic conditions. It may present with cosmetic problems such as deep superior sulcus, pseudoptosis or eyelid retraction; or functional problems such as diplopia or exposure keratopathy. There are three main pathogenic mechanisms: structural alterations in the bony orbit; orbital fat atrophy; and retraction. Evaluation of enophthalmos patients includes orbital imaging and a thorough ophthalmic and systemic examination. In this review, we discuss the presenting features of non-traumatic enophthalmos and include a brief description of the more important causes. An approach to the clinical evaluation of these patients is also discussed together with a brief overview of the principles of management.