one test for dry eye is known as the
tear breakup time test the tear breakup
time test can provide an important
measurement of how well a patient's
tears wet and protect the eyes surface
for this test a small amount of
fluorescein dye will be applied to the
eye so that it mixes with the tear film
the patient is asked to blink and then
ask 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 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 the tear film has
broken up
if tear breakup occurs in a very short
time it may be an indication of dry eye