What is the name of the small elastic duct located on the nasal side of the upper eyelid?

The name of the small elastic duct located on the nasal side of the upper eyelid is the lacrimal canaliculus. This structure is essential in the drainage of tears from the surface of the eye into the nasolacrimal system. Each lacrimal canaliculus serves as a channel that leads tears into the lacrimal sac, from which they eventually flow into the nasal cavity.

The lacrimal duct terminology often refers to a broader anatomical structure that encompasses the entire system involved in tear drainage, but it is not specific to the small duct located on the upper eyelid. The palpebral fissure is the opening between the eyelids, and the term "tear duct" is commonly used to refer to the entire system, but lacks the precision of anatomical terms needed in a clinical context. Thus, the lacrimal canaliculus is the most accurate response to identify the specific duct in question.