Palpebral fissure refers to the opening between the upper and lower eyelids. The term is commonly used in medical settings, particularly in ophthalmology. Synonyms for palpebral fissure include eye aperture, interpalpebral fissure, and eyelid cleft. Other terms that can be used to refer to the same body part include eye slit, eyelid opening, and ocular fissure. The use of synonyms can help make medical language more accessible to people outside the field. While palpebral fissure may be the most precise term for describing the eyelid opening, using simpler language can make medical information easier to understand for patients.