Which component is primarily assessed in a Schirmer test?

The Schirmer test is designed specifically to measure tear production to assess the function of the lacrimal glands. In this test, small strips of filter paper are placed in the lower eyelid for a specified period. The amount of moisture on the paper indicates how much tear fluid has been produced. This is critical for diagnosing dry eye conditions and determining the underlying cause, which can inform appropriate treatment options. Therefore, the primary focus of the Schirmer test is indeed on tear production, which is vital for maintaining ocular surface health and comfort.

The other options pertain to different aspects of eye health; for instance, corneal thickness is typically evaluated using tools such as pachymetry, visual acuity is assessed using an eye chart, and iris strain is not a standard assessment in ocular examinations, further emphasizing the distinct role of the Schirmer test in evaluating tear production.