Dry eye occurs when the eyes produce too few tears or the tears evaporate too fast. The condition can affect one or both eyes. Lifestyle changes can help, but in severe cases, a person may need medication or surgery.
Dry eye can be mild to severe. Possible symptoms include eye pain or discomfort, blurred vision, and increased sensitivity to light.
This article outlines the symptoms and causes of dry eye and discusses some risk factors for the condition. We also provide information on diagnosing, treating, and preventing dry eye and discuss some possible complications of the condition.
Dry eye syndrome may cause a range of symptoms, including:
- eye redness or soreness
- excessive tearing
- a stinging or burning sensation in the eyes
- a sensation of grit in the eyes
- stringy mucus in or around the eyes
- eye sensitivity to smoke or wind
- sensitivity to light
- blurred vision, especially towards the end of the day
- double vision
- eye fatigue after reading, even for a short time
- difficulty keeping the eyes open
- discomfort when wearing contact lenses
- eyelids sticking together when waking up
Some people experience intense eye pain, which may lead to anxiety and difficulty with daily functioning.
Healthy eyes have a constant covering of “tear film,” which is a fluid membrane that enables clear vision and prevents the eyes from becoming dry. Tear glands are responsible for the production of tears.
The main causes of dry eye are insufficient tear production and an imbalance in the tear mixture, which makes them evaporate too quickly.
Imbalance in the tear mixture
The tear film consists of three layers: oil, water, and mucus. Problems with any of these can lead to dry eye symptoms.
The top layer of the tear mixture consists of oil that derives from the meibomian glands in the edges of the eyelids. The oils help to smooth the tear surface and slow down the rate of tear evaporation. Faulty oil levels can cause the tears to evaporate too quickly.
Certain conditions can block the meibomian glands, interrupting oil production and making dry eyes more likely. Examples include the inflammatory eyelid condition blepharitis and the inflammatory skin condition rosacea.
The middle layer of the tear mixture is the thickest and consists of water and salt from the tear, or “lacrimonial”, glands. The water and salts help cleanse the eyes by washing away particles and irritants.
Problems with the middle layer can lead to tear film instability. If the water layer is too thin, the oil and mucus layers may touch each other, resulting in a stringy discharge that is characteristic of dry eyes.
The inner layer consists of mucus that enables the tears to spread evenly over the eyes. Problems with the inner layer can lead to dry patches on the cornea, which is the clear membrane that sits in front of the iris and pupil of the eye.
Reduced tear production
By the age of
Below are some factors that may increase a person’s risk of developing dry eyes.
Each time a person blinks, their eyelids spread a thin film of tears across the surface of the eyes. Eyelid issues can affect the blinking motion that spreads the tear film evenly across the eyes. Examples of such issues include:
- ectropion, in which the eyelid turns outward
- entropion, in which the eyelid turns inward
- blepharitis, which is inflammation of the eyelid
Wearing contact lenses can also affect the blinking motion, causing dry eyes.
Other medical conditions
Certain medical conditions may reduce tear production. Examples include:
- vitamin A deficiency
- autoimmune diseases, such as:
- radiation therapy
Certain environmental factors can affect the rate of tear evaporation. Examples include:
- climatic factors, such as dry, hot, or windy weather
- indoor heating or air conditioning
- high altitude
- exposure to smoke
- use of contact lenses
Other environmental factors may increase visual concentration and slow down blinking rate, causing the eyes to become dry. Examples include:
- using a computer monitor
The following medications and medical procedures can cause or contribute to dry eyes:
- some diuretics
- some sleeping pills
- angiotensin-converting enzyme (ACE) inhibitors
- birth control pills
- some antidepressants
- some acne drugs, specifically isotretinoin-type medications
- morphine and other opiate-based pain relievers
- refractive eye surgeries, such as laser-assisted in-situ keratomileusis (LASIK), which may temporarily increase the risk of dry eyes
In order to diagnose dry eye, a doctor will ask about a person’s symptoms and examine the front of the eye. They
The dilated eye exam can provide information on the following:
- the amount of tears the eyes are making
- the rate of tear evaporation
- the structure of the eyelids
A doctor will also review a person’s medical history and ask about any medications or supplements the person is taking.
The treatment for dry eye aims to:
- restore or maintain adequate tear levels
- reduce dryness and discomfort
- maintain overall eye health
Depending on the cause of the dry eye, treatment may involve one or more of the following methods:
- adding tears
- conserving tears
- increasing tear production
- treating underlying causes
Below is more information on these and other approaches.
A person can often treat mild cases of dry eye using OTC artificial tears. A pharmacist can recommend the most suitable product to use.
In general, people should avoid products containing preservatives and other additives as these can further irritate dry eyes.
It can be helpful to apply eye drops before doing activities that tend to exacerbate dry eye symptoms. Ointments are better for nighttime use as they may temporarily blur vision.
The aim of this method is to keep tears within the eye for longer in order to prevent dry eyes. This can involve blocking the tear ducts that drain the tears out of the eyes.
A temporary solution involves blocking the tear ducts with tiny silicone or gel-like plugs. A more permanent solution involves surgery to close the tear ducts.
Increasing tear production
A doctor may prescribe eye drops to increase tear production. A person who experiences severe or persistent dry eyes
Treating underlying conditions
How doctors approach underlying conditions that could be causing dry eyes will depend on the illness. For example, they may prescribe topical or oral antibiotics to treat bacterial blepharitis, or alter a person’s treatment plan for an autoimmune disease to better control it.
Home care can help relieve some of the symptoms of dry eyes. A doctor may suggest:
- cleansing the eyelids with a prescription eyelid cleanser to remove oil and bacteria
- applying warm compresses to the eyelids to relieve pain or soreness
- gentle eyelid massage
According to the
Sources of vitamin A include:
- oily fish
- milk and yogurt
- red vegetables
- green leafy vegetables
A 2019 meta-analysis of 17 randomized clinical trials found that Omega 3 fatty acid supplementation significantly improved the signs and symptoms of dry eye disease when compared with a placebo. The study authors concluded that Omega 3 supplementation might be an effective treatment for dry eye.
Sources of omega 3
- oily fish
- flax seed
- canola oil
Thermal pulsation systems
These devices stimulate the meibomian glands, helping people with meibomian gland disorders. They work by delivering heat and pressure. Some examples include Lipiflow and Tear Care.
Intense pulsed light
Intense pulsed light (IPL) is a type of light therapy with a range of uses. People are increasingly using it to treat dry eye that is the result of meibomian gland dysfunction. A medical professional carries out this procedure in their office or clinic.
According to the
The American Optometric Association offers the following tips for helping to prevent dry eyes:
- blinking regularly when reading or staring at a computer screen for extended periods
- wearing sunglasses with wraparound frames when outdoors to protect from climatic causes of dry eye
- avoiding dry outdoor environments
- using a humidifier to increase indoor humidity at work and at home
- drinking plenty of water to avoid dehydration
- asking a doctor for advice about supplements to take for dry eye
Many mild cases of dry eye do not cause complications. However, severe or persistent cases can lead to complications, such as conjunctivitis or corneal ulceration or scarring.
Conjunctivitis is the medical term for inflammation and swelling of the conjunctiva, which is the thin, transparent membrane covering the white of the eye. Most cases of conjunctivitis resolve with appropriate treatment. However, severe cases can cause serious complications, such as blindness.
Ulceration and scarring of the cornea may cause pain as well as permanent changes to a person’s vision.
The symptoms of conjunctivitis and corneal scarring can be similar to those of dry eye. A person should seek