Andrew A. Dahl, MD, is a board-certified ophthalmologist. Dr. Dahl's educational background includes a BA with Honors and Distinction from Wesleyan University, Middletown, CT, and an MD from Cornell University, where he was selected for Alpha Omega Alpha, the national medical honor society. He had an internal medical internship at the New York Hospital/Cornell Medical Center.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
If blinking is decreased or if the eyelids cannot be closed, the eyes may dry out because of tear evaporation.
When you read, watch TV, or perform a task that
requires close attention with your eyes, you may not blink as often. This
decreased blinking allows excessive evaporation of the tears.
Certain conditions, such as stroke or Bell's palsy, make it difficult to close your eyes on your own. As a result, your eyes may become dry from tear evaporation.
Abnormal production of mucin by the conjunctiva may occur.
This can result from chemical (alkali) burns to the eye or
as a result of different autoimmune diseases, such as Stevens-Johnson syndrome and cicatricial pemphigoid.
This abnormal production of mucin leads to poor spreading of the tears over the surface of the eye. The surface of the eye can dry out and even become damaged, even though more than enough watery tears may be present.
Insufficient lipid layers are the result of meibomian gland
dysfunction, as with rosacea or
as a result of taking oral isotretinoin medication.
Meibomian glands are the oil glands in the eyelids
that produce the lipid layer.
If the oil glands become blocked or if the oil is too
thick, there may not be enough oil to cover the watery tear layer to prevent
Also, if an infection is present along the eyelids or the eyelashes, called blepharitis, the bacteria may breakdown the oil so there may not be enough oil.
Dry eye is a multifactorial disease of the tears and the ocular surface that results in symptoms of discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface.