Schirmer Test

Excerpt

The Schirmer test or Schirmer tear test (STT) is used to assess tear production, especially in patients with suspected keratoconjunctivitis sicca, dry eye, or tear overproduction. The test works by the principle of capillary action, which allows the water in tears to travel along the length of a paper test strip in an identical fashion as a horizontal capillary tube. The rate of travel along the test strip is proportional to the rate of tear production.