Dry eye syndrome
Our eyes are constantly coated with a film of tears to ensure clear vision and protect from dryness. Dry eye syndrome, also known as keratoconjunctivitis sicca, occurs when there are changes to the quantity or quality of these tears.
Symptoms usually affect both eyes and may include the following:
- Blurred vision
- Redness
- Burning
- Itching
- The sensation of having something in your eye
- Sensitivity to light
- Stringy mucus in or around your eye
- Excess tear production
The last symptom may seem out of place, but it is actually a common reaction to dryness caused by poor tear quality.
Causes and triggers
There are two main types of dry eye syndrome: the first occurs when your eyes don't produce enough tears, while the second occurs when your tears evaporate too quickly. It's possible for a person to experience both at the same time.
Insufficient tear production may be caused by the following:
- Aging
- Use of certain medications
- Hormonal changes, particularly in women (e.g., pregnancy, menopause)
- Difficulty blinking normally
- Certain diseases (e.g., diabetes, Sjögren's syndrome, thyroid disorders)
When tears evaporate too quickly, it's often because the Meibomian glands aren't working properly. These glands produce an oil that helps tears adhere to the eye for longer. Note that Meibomian glands are not the same as lacrimal glands, which produce tears. This type of dryness can be caused by the following:
- Meibomian gland blockage
- Allergies
- Use of certain medications
- Eyelids that turn inward or outward
- Environmental conditions (dry or smoky air, windy weather)
- Not blinking enough (for example, when staring at a screen for long periods)
If left untreated, dry eye syndrome can affect your quality of life. In the most severe cases, scars and ulcers may form on the surface of the eye. In the long term, this can result in blurred vision.
Treatment
Treatment for dry eye syndrome varies based on the symptoms and their cause. It may be necessary to try several treatments to find the right solution. For example, you might need to control your diabetes or modify the dose of a medication.
Applying artificial tears is usually enough to relieve symptoms. These are available without a prescription and come in a variety of forms. Ointments lubricate longer than eye drops, but may cause blurriness. For this reason, it's best to apply them just before bedtime. Avoid products that relieve eye redness, as they can become an irritant when used for prolonged periods. Certain formulations do not contain preservatives, which can also irritate the eye. Your pharmacist can help you decide which product is right for you.
Prescription products that reduce inflammation or stimulate tear production are also available. It may also be necessary to temporarily or permanently block your tear ducts. In this case, a plug is inserted into the small openings in the inner corners of the eyelids to prevent natural or artificial tears from draining through them. Other treatments include specially designed contact lenses and surgery.
Here are some examples of lifestyle changes that can prevent or alleviate symptoms:
- Avoiding smoke
- Using a humidifier in the bedroom
- Applying a warm compress to the eyes to stimulate the Meibomian glands
- Keeping air from blowing into your eyes (e.g., hair dryer, air conditioner)
- Blinking more often or taking breaks (e.g., while reading or when looking at screens)
When should I see a health care professional?
Consult your health care provider in the following cases:
- Your symptoms do not improve after 3 to 4 weeks despite preventive measures
- You are experiencing sensitivity to light or eye pain
- You have eye irritation or redness since several days