Tear Break Up Time Test for Dry Eye

One test for dry eye is known as the tears break up time test. The tear break up time test can provide an important measurement of how well the patient’s tear wet and protect the eye surface. For this test a small amount of fluorescine dye will be applied to the eye so that it mixes with the tear film. The patient is asked to blink and then asked to keep their eye open for the doctor to see. After each blink, the tear film will thin and evaporate, forming dry spots due to insufficient wetting of areas on the eye’s surface. While the patient holds their eye open, the doctor measures how long it takes for the first dry or dark spot in the tear film to appear, indicating that the tear film is breaking up. If tears break up occurs in a short time, it may be a indication of a dry eye.

Tear break up time  is a  test used to verify if you have evaporative dry eye disease.  For this test, a small quantity of fluorescein is instilled into the patient’s tear film and the patient is asked not to blink while the tear film is observed under a blue light.  The break up time is recorded as the number of seconds that elapse between the last blink and the appearance of the first dry spot in the tear film.  In general, a tear break up time test for dry eye under 10 seconds is considered abnormal.