A Schirmer test measures your tear production. It is often conducted when your eye care professional sees a lack of a tear pool during the initial slit lamp examination and finds dry areas in one of the stain tests. Your eye care professional will take a special strip of filter paper, put a tiny fold in it and place it on the tear pool on the edge of the lower eyelid. The paper remains in place for five minutes, absorbing the tears. The test produces no pain, but some people find it slightly uncomfortable. It does not affect vision. After five minutes, the paper strip is removed and the area of wetness measured in millimeters (mm). A wetness area of 10 mm or above is normal. A reading of less than 10 mm is below normal, but most people can tolerate it and may have a few symptoms. A reading of less than four mm is considered severe, and most people at this level do have some symptoms.