What does the Jones test assess in the eye?

The Jones test is specifically designed to assess nasolacrimal patency, which refers to the openness and functioning of the tear drainage system that connects the eye to the nasal cavity. In performing the Jones test, a colored dye is introduced into the conjunctival sac of the eye. If the nasolacrimal system is patent, the dye will flow through the tear ducts into the nasal cavity, confirming that the drainage pathway is unobstructed. This test is particularly useful for diagnosing conditions like epiphora, where an overflow of tears occurs due to blockage or dysfunction of the nasolacrimal system.

In contrast, the other options focus on different aspects of ocular health. Lens clarity pertains to the transparency of the lens and is assessed through techniques such as slit-lamp examination or retinal imaging. Corneal integrity relates to the health and transparency of the cornea, often evaluated through fluorescein staining or direct examination for signs of ulceration or other diseases. Pupil diameter refers to the size of the pupils and can indicate changes in neurological status or response to light but does not provide information about the nasolacrimal drainage system. Thus, the choice that correctly represents what the Jones test evaluates is nasolacrimal patency.