The human eye relies upon the regular flow of tears to provide constant lubrication and moisture for the maintenance of comfort and eye vision. Tears are a combination of oils, which help to provide lubrication, water which provides moisture, and mucus that allows them to spread properly across the surface of the eye. Tears also include a selection of special proteins and antibodies which help individuals to resist possible infection.

Dry Eye

The components of tears are secreted from glands around the eye, and when one of those glands is damaged, or the production of tears is altered in some way, it’s likely that a person will begin to suffer discomfort in the form of dry eye syndrome. When tears cannot lubricate the eye as they should, this leads to a feeling of dehydration around the eyes, which can cause symptoms like:

• Light sensitivity
• Pain and discomfort
• Gritty or sandy feelings
• Redness
• Itching
• Blurred vision

One frequent symptom of dry eye that confuses many patients is the appearance of excess tears which may overflow and run down the cheek. Often, these tears do not have the right balance to provide proper lubrication for the eye, and though they can wash away foreign bodies, they will not assist with the symptoms of dry eye. The reason for this is that when your eyes tear up excessively, the moisture is made up mostly of water, which cannot properly coat the eye surface.

Unfortunately, because the symptoms of dry eye are often associated with a variety of different disorders, it is crucial to see a doctor if you want to be sure about your condition. Often, the dry eye condition can be treated and diagnosed when recognized by an optometrist, or an ophthalmologist.

What to Expect from a Dry Eye Exam?

Before your eye doctor conducts any specialist tests, if it is has been more than 12 months since your last exam, he or she will need to perform several tests in determining your ocular health and visual abilities. Your doctor will look at the overall appearance of your eye and any surrounding tissues, and check for symptoms such as drooping eyelids, squinting, or improperly working facial muscles. At this point, most doctors will also conduct a test for proper pupil function using a light pen.

During the exam, a comprehensive doctor should perform the following checks:

• Confrontation fields – a test of peripheral vision
• Color vision
• Stereopsis – your ability to see in three dimensions
• Point of accommodation – the closest point at which you can see an image clearly
• Near convergence – the point at which both eyes can see an image together
• Eye alignment

If any of the tests above suggest a potential problem, more extensive tests may be required at a later stage of the exam. On the other hand, if an eye examination has already been conducted recently, your doctor may choose to focus completely on the symptoms you are experiencing.

Checking Dry Eyes

During a dry eye test, your doctor will begin by examining the exterior structure of the eye, including the eyelids to track down any signs of irritation or problems. They will also conduct a slit lamp examination of the margins of each eyelid, looking into the Meibomian glands for any sign of problem. The Meibomian glands are located inside of the eyelids, and can supply the outermost layer of the tear film responsible for protecting your eyes. Your doctor may also use the slit lamp to look for debris in the tear film that suggest the eye is not properly cleansed by tear flow.

After an initial examination, there are a wide variety of procedures available to doctors that can help with checking the composition and quantity of tears. Several are often utilized to ensure that a proper diagnosis is made, and some of these tests include the use of fluorescein dye, while others utilize filter paper to check the quality of the tears produced.

The Schirmer’s Test

One of the most common tests used to identify the significance of a dry eye problem is the Schirmer’s test, which assesses how quickly your eyes can produce tears. A Schirmer’s test most commonly diagnoses dry eye syndrome, which occurs when the tear glands are not able to produce enough tears. What is important, however, is that a Schirmer’s test can also determine whether your eyes are producing too many tears.

The Schirmer’s test is often referred to as the:

• Basal secretion test
• Tearing test
• Tear test
• Dry eye test

What to Expect from the Schirmer’s Test

There is no special way in which patients should prepare for the Schirmer’s test, however, doctors often recommend that if you wear contact lenses, you should bring your glasses to your appointment. The reason for this is that following the test you will need to avoid wearing contact lenses for at least a couple of hours.

During the test, your doctor will request that you remove your glasses and contact lenses, and will then place numbing drops in your eyes. The drops are given to help ensure that your eyes don’t begin to water in reaction to the test strips that are used. The numbing drops you are given may cause very temporary stinging or irritation, but this will disappear fairly quickly. Once you have been properly numbed, your doctor will pull your lower eyelid out and place a strip of special paper beneath the lid. He or she may choose to test both eyes at the same time.

Once the paper has been inserted, you will need to close your eyes and keep them shut for about five minutes while keeping the paper in place. During this period, it’s crucial to avoid touching or squeezing your eyes, as this can alter the results.

After about five minutes, your doctor will carefully remove the paper strips and measure the amount of moisture that has gathered on each. In an alternative option to the Schirmer’s test, your doctor may decide to test tear production with a test known as the red thread examination. While the red thread examination uses the same premise as the Schirmer’s test, it utilizes a thread in place of paper strips.

The Results of a Schirmer’s Test

If you have healthy tear production, then you should find that the Schirmer’s test shows around ten millimeters of moisture for each strip. If the test results show less than ten millimeters of water, this is an indication that you suffer from dry eye syndrome. On the other hand, if there are more than ten millimeters of moisture, this could also indicate that you have more tear production than is necessary.

Usually, if the results of the Schirmer’s test are abnormal in any way, further testing will be required to diagnose the specific cause of the problem and find adequate treatment.

Resources and References:

The challenge of dry eye diagnosis – In depth study about dry eye diagnosis. (NIH.gov)

Tests and diagnosis– The basic tests and diagnosis methods used for dry eye syndrome. (Mayo Clinic)

Schirmer’s Test (Dry Eye Test) – Basic information about the Schirmer’s test. (Healthline.com)