Dry Eyes Have Many Causes

Dear Dr. Eva,

I am having awful problems with dry eyes.  My eyes feel really dry all the time and sometimes they hurt. It’s been going on for months. I thought it might be allergies, but allergy pills didn’t help. I’ve tried different kinds of eyedrops, and they didn’t help much. I don’t have medical insurance. Can you suggest something?

Dry Eye

 

Dear Dry,

There are two major causes for dry eyes. The eyes make several different kinds of fluid that work together to keep the surface of the eyes moist.  When there is not enough of any of these fluids, eyes can feel dry and irritated.

The fluid on the eye surface, called the tear film, has 3 different layers, which can be seen by eye doctors using specialized equipment. These layers are:

• The oily (lipid) outer layer, made by the tiny meibomian glands that line the edges of the upper and lower eyelids. This oily fluid keeps tears from evaporating too quickly from the eye surface and keeps the surface of the eyes smooth.
• The watery (aqueous) middle layer, made in the lacrimal glands (tear glands) which are located above the the outer corner of the eyes. Lacrimal fluid, which is what we think of as tears, keeps the eyes moist. It is a thin, salty fluid that continuously drains over the entire eye, like a curtain. When it is produced in larger amounts, such as when there is an irritant in the eyes or when a person is crying, it drains in tears from the lacrimal ducts at the inner corners of the eyelids.
• The inner mucus (mucin) layer is produced by the epithelial cells, which are the outermost layer of the eyes. The mucus layer helps the tear film stick to the surface of the eyes.
• Dry eyes usually result from either a lack of tears or a lack of oil.

Dry eyes due to lack of tears eyes can be relieved with saltwater solutions like Tears Naturale and many others,

When saltwater eye drops aren’t helpful for dry eyes, it is often because eyes have enough tears, but not enough oil. There are two treatments for lack of eye oil. Some eye drops  are designed to work the same way as the eye’s natural oil. Two brands of these are Thera Tears and Refresh.

All eye drops mentioned in this article are available without a prescription. It’s most effective to use eyedrops several times a day, not just when your eyes feel dry. It is safe to use these eye drops as often as you need to.

In addition to oil-replacement eyedrops, many people with dry eyes caused by lack of oil find it helpful to take capsules of fish oil, also called omega-3 fatty acid supplements, 2000 mg or more, one a day. It may take a few weeks to feel the benefit of these, but if they are effective for you, if you continue taking them you may not need to use eyedrops at all.

Other possible causes of dry eyes to consider:

• Overly dry air due to air conditioning or heating
• Allergy to something you are putting on or near your eyelids, like makeup or moisturizer
• Irritation from contact lenses
• Medicine: many medicines can make the eyes and mouth feel dry

Signs that dry eyes could be part of a more serious condition: Dry mouth, vision loss,  rashes, pain and swelling in several joints, high blood sugar.

Of course, it is best to see an eye doctor (optometrist or opthalmologist) to make a definite diagnosis. If neither type of eyedrops work for you, please try to do that. You may be able to find eye care at a less expensive rate through a community health center. Also, some private eye doctors have reasonable rates for uninsured people.