Tears are essential for the health of the eyes. They keep the ocular surface lubricated and smooth and help them focus light for clear vision. They are also helpful in keeping the eyes clean of debris and dirt. Every time you blink, the eyelid helps spread a thin tear film across your entire eye.

So, what happens if there is a problem with your tears? A condition known as dry eye is the most common result of tear problems. Dry eye is a condition where you either have unstable or inadequate tears. It can affect either one or both eyes, and it causes significant discomfort.

So, what is dry eye, and what are the symptoms?

What Causes Dry Eye?

Dry eyes can occur due to two leading causes: inadequate or unstable tears. Insufficient tears mean your eyes are not producing enough tears to keep your eyes lubricated throughout the day. Unstable tears can occur due to a lack of one of the essential parts of tears.

Inadequate Tears

One of the primary causes of dry eye is inadequate tear production. When you do not have enough tears, your eyes will dry out several times throughout the day. The scientific term for this is keratoconjunctivitis sicca. 

 

Inadequate tears can occur due to a few factors:

 

• Aging

• Medical conditions such as rheumatoid arthritis, scleroderma, Sjogren’s syndrome, graft vs. host disease, thyroid disorders, lupus, vitamin A deficiency, or allergic eye disease

• Nerve damage to the eye due to contact lens use or laser eye surgery

• Reactions to medications like antidepressants, hypertension drugs, birth control, and acne

Unstable Tears

The second primary cause of dry eyes is unstable tears or poor-quality tears. It mainly occurs when there is a problem with one of the essential layers. Tears have three main layers that allow them to lubricate the eyes efficiently. Each part plays a specific role. The three main layers of tears are:

1. Lipid Layer

The lipid layer of the tear film is the top layer. The lipids that form this layer are produced in the meibomian glands in the eyelids. Their primary function is to protect the other layers from evaporation and smoothen the eye’s surface. 

 

When the lipid layer is not enough, the tears evaporate very quickly, leaving the eyes open to the elements. Issues with the lipid layer stem from a problem with the meibomian glands.

 

2. Aqueous Layer

The second and middle layer of the tear film is the aqueous layer and is the thickest of the three layers. It comprises water and salt. It originates in the lacrimal glands, also known as the tear glands. The aqueous layer helps keep the eyes clean and separates the outermost and top layers.

When there is an issue with this layer, the lipid and mucin layer touch and form a stringy discharge. Some people with dry eyes may notice this symptom.

 

3. Mucin or Mucus Layer

The bottom and last layer of the tear film is the mucin or mucus layer. Its primary function is to help the tear film spread evenly across the ocular surface. When there is an issue with this layer, the eye may develop dry patches across the corneal surface.

For more information on dry eye disease, contact Chroma Optics at our office in Burlington, Vermont. Call (802) 497-1676 to book an appointment today to get evaluated for dry eye.