The human tear layer has three main layers. The mucin layer is closest to the eye. The aqueous or water layer is in the middle and the lipid or oil layer is the outermost.
Studies report that upwards of 80% of dry eyes are the result of a lipid layer deficiency. The oil for the lipid layer of the tears comes from the meibomian glands.
When these meibomian glands do not release the oil into the tears in an efficient manner we refer to that as a condition named meibomian gland dysfunction (MGD).
One of the main causes of MGD may well be tied to a patient’s blink rate. Theories suggest that the lack of a full or complete blink can result in less pumping activity of the lower eyelid meibomian glands, which are responsible for 78% of the oils in the tear film.
The pumping action occurs during a blink because a muscle named the Riolan muscle surrounds the meibomian glands and is only activated when the eyelids come together during a blink. A partial blink or an incomplete blink will not activate the Riolan muscle.
A partial blink may have many causes including lagophthalmos, use of digital devices such as computers, tablets and smartphones, cosmetic surgery and simply an inability to blink that has been learned or developed over years. The average person using a computer blinks 4.4 times per minute as opposed to someone who is gazing (21 blinks per minute) or in conversation (over 30 blinks per minute).
Eyelid Exercises do two things: 1. They make up for missed blinks and 2. They strengthen the Riolan muscle and make our blinks more productive to release more oil from the meibomian glands.