Dry eyes are a result of an inadequate delivery of moisture, or tears, to your eyes. Sometimes dry eyes occur because the body does not have the means to produce the necessary amount of tears. Other times, your tears may lack the appropriate properties and chemical balances required to stay lubricated.
Your tears not only lubricate your eyelid and eyeball, they also protect your mucous membranes from dryness and dehydration. Tears also wash dust and other foreign bodies from your eyes, while simultaneously coating them in lysozyme (a strong antiviral and antibacterial).
Tears by Design
Your tears are made up of three important layers: oil, water and mucous.
The oil layer is on the outer surface and contains lipids, or fatty acids. This layer is produced by your meibomian glands (tiny glands in your eyelids). If not producing properly, the watery layer evaporates and quickly causes dry eyes.
The water layer is made up of water and proteins produced by your lacrimal glands (located just below your eyebrow). If this layer does not produce enough moisture, the oil and mucous layers will mix and create a thick discharge.
The mucous layer forms in the conjunctiva, the clear membrane that covers the white of your eye, and covers the cornea. Without this mucous, the cornea will dry and your vision will become increasingly difficult.
If the concentration of properties within any these three layers are altered or inadequate in any way, dry eyes may result. If you’ve experienced an oil, water or mucous deficiency, please contact your eye doctor for a thorough examination.
Further, those with a thin tear film may not be able to wear contact lenses. Because the eye has a thin tear film, more oxygen is needed for the eye to remain healthy – contacts will decrease oxygen flow and cause dry eyes. For lenses with enhanced oxygen circulation, check out Acuvue Oasys, BioTrue 1 Day lenses by Bausch & Lomb, or Air Optix brand contacts.
Common Causes of Dry Eyes
While dry eyes usually occur due to a lack of tear production, the source can also be physical or environmental. The following are some such common causes:
- Age. As your age goes up, your tear production goes down. People older than 50 often experience dry eyes.
- Health. Lupus, diabetes, rheumatoid arthritis, thyroid conditions and other disorders will decrease the eyes ability to form tears.
- Gender. Dry eyes are most common in women; especially in postmenopausal women.
- Medication. Blood pressure medications, birth control pills, decongestants and antihistamines can all cause dry eyes.
- Tear Glands. Damaged tear glands due to an accident, infection, injury or radiation treatments can decrease tear production.
- Diet. A diet lacking Vitamin A (broccoli, carrots, sweet potatoes, kale) and Omega-3 fatty acids (flax seed, salmon, brussel sprouts, walnuts, shrimp) may result in decreased tear production.
Call Your Doctor
When you have difficulty with dry eyes, you may experience any number of symptoms including:
- Blurred vision.
- Sensitivity to light.
- A gritty feeling (like sand or dust in your eye).
To combat these symptoms, over-the-counter eye drops often help. On the other hand though, if your symptoms are continuous or recurring, call your doctor to uncover the underlying problem. A thorough eye examination will include the Schirmer test – used to measure the rate/amount of tears produced – and others to determine the overall quality of your tears. After a diagnosis, your doctor will be able to recommend the course of treatment for your specific eyes.