Dry eye syndrome: symptoms, causes, treatment, eye drops

Burning, pain and any breeze makes it look like there are needles entering your eyes. Sounds familiar?

You may be experiencing dry eye syndrome, a condition that affects thousands of people and that can cause serious problems with vision quality over time.


What is dry eye syndrome?

Dry eye syndrome, also known as lacrimal dysfunction syndrome or dry keratoconjunctivitis , is a condition in which the composition or production of the lacrimal glands is inadequate, causing the lack of tears or their rapid evaporation.

Tears are not just what comes out of our eyes when we cry. They have the function of lubricating our eyes, protecting them from dryness and bacteria.

They are composed of innumerable elements, such as mineral salts, fat and water. These elements, in addition to guaranteeing the functions already mentioned, also prevent the tears from evaporating too quickly.

When the tear composition is altered, this evaporation occurs before the next blink, which in the course of time can make the eyes dry and cause vision problems, among other symptoms such as burning and itching.

The condition can have several causes, it can affect anyone and it is very common, especially when the age gets closer.

It is estimated that dry eye syndrome affects between 5% and 34% of the world population and approximately 70% of the elderly have it.

How does dry eye syndrome affect the tear glands?

There are two main types of dry eye syndrome and they differ by the way the condition affects the eyes. These forms are:

Evaporative dry eye

One of the ways in which the eye can get dry is by evaporating the tears that can happen faster than expected.

This can happen for several reasons, which in general cause the chemical composition of tears to change or the frequency of blinks to change.

Tears are made up of water, minerals and other chemical compounds that protect the eyes from bacteria, but there is also a layer of fat.

It is this fat that protects the tear from rapid evaporation that would affect it if it were made up only of water and minerals. It also gives stability to the tear film, which is the tear layer that remains in the eye.

After a few seconds – approximately 12 – the tear film breaks and a new layer must be “applied”, which the body does by blinking and adding more tears through the tear glands.

When the amount of fat in the tear composition is reduced, evaporation increases and we need to produce more tears to compensate, which is not always the case. So, the result is dryness.

Another method of evaporation is the lack of blinking.

The blinks are used to spread the tears and mix their components in the eyes. If you don’t blink enough, the fat and water are completely separated and evaporation is facilitated.

Dry eye due to production deficiency

In some cases, what affects ocular lubrication is not evaporation, but simply the amount of liquid.

If your tear glands don’t produce enough tears, your eyes become dry.

Several conditions can cause a reduction in production, but the result is invariably the same: dryness.

Mixed dry eye

The mixed dry eye happens due to a mixture of the two previous types. In this case, the quantity of tears produced is low and at the same time they are of low quality.

Its composition causes the few tears produced to break and evaporate very quickly, causing dry eye syndrome.

How does tear work?

Tears are essential for eye health. Its main functions are to lubricate the eyes and protect them .

Bacteria, wind, heat, dust, all of these can damage the eyes and the tear film, which is a layer of tears that stays in the eyes, prevents this from happening.

The tear film is composed of water, mucus (which contains mineral salts and other substances) and a layer of oil. It is oil, for example, that protects tears from excessively rapid evaporation.

The mixture of water with mucus prevents dust from reaching the eyes, blocks bacteria and prevents heat and wind from dehydrating the eye cells.

The tears, which are created in the tear glands, are then drained through the tear ducts and replaced. Dry eye syndrome is due to the dryness of the tear film.

Quality of tears

Even if you have enough tears, when the makeup is inadequate, some problems like dry eyes can arise.

If the amount of oil is small, evaporation happens too quickly.

If there is little water, the tear film can become too viscous and the vision is blurred. In the absence of mucus, it is easier for objects and bacteria to come into contact with the eyes.

Therefore, tear quality is just as important as quantity.


The causes of dry eye syndrome are diverse. Some of them are:


The amount of hormones released in the woman’s body during pregnancy alters various functions of the body.

The same situation that makes pimples more common in these women can cause the production of the oil, which protects tears from evaporation, to take longer.

The result of this is that the tears, although produced in an adequate amount, can evaporate too quickly, leaving the eyes dry.

This change can affect women from pregnancy to breastfeeding.


The climacteric, which is often called menopause , is the transition period between the reproductive and non-reproductive period of a woman’s life, and in the end, it culminates in menopause, which is the last menstrual period.

The symptoms popularly attributed to menopause are actually climacteric. These symptoms involve hormonal changes that can trigger dry eye syndrome.

It is common that it occurs in women of advanced age because, in addition to the climacteric, changes in age are also causes of the syndrome. So, both factors increase the chances.

Read more: Menopause phases: pre, peri (climacteric) and post


Like pregnancy and menopause, contraceptives cause changes in the amounts of female hormone in the woman’s body, which can trigger a dry eye syndrome.

Excessive exposure to screens

The very frequent use of screens (computers, tablets, cell phones) causes the frequency of our blinks to be reduced.

Over time, this can cause dryness in our eyes, as less blinking reduces lubrication and facilitates evaporation.

Read more: Children on cell phones: overuse causes developmental delay

Chronic conjunctivitis

Conjunctivitis is inflammation of the conjunctiva (the layer that covers the sclera, which is the whites of the eyes, and the inner part of the eyelid), often caused by infections.

When these infections are frequent, the tear ducts may show reduced production.


The blepharitis is a chronic inflammation of the eyelids. It can affect tear production and has dry eyes as one of its symptoms. As the disease is chronic, treating symptoms is the best way to maintain eye lubrication.

Meibomian gland dysfunction (DGM)

DGM is a common disorder, but few people know it. The meibomian glands are located on the eyelids and secrete oil into the eyes.

This oil is part of the tear composition and protects tears from evaporation too quickly.

When the glands are not functioning properly, the production of this oil is reduced and the dry eye syndrome by evaporation can set in, as this way the tears evaporate faster.

This dysfunction is believed to be one of the biggest causes of dry eye, but it is a little known condition and there is no effective treatment for it.


The cigarette releases smoke, which favors the dryness of the eyes, causes eye irritation and facilitates tear evaporation.


Antidepressants, antiallergic agents, diuretics, beta-blockers and the aforementioned contraceptives can alter several factors in the body that affect tears.

Both the tear quantity and its composition can be altered by drugs.

Eye surgeries

Eye surgeries can cause damage or inflammation in the eyes and their structures, thus impairing the production of tears for eye protection.

The result is dry eye syndrome, which has the classic symptoms of dry eyes.

Lack of vitamin A

The lack of vitamin A in the body affects eye lubrication, making the eyes more dry. Vitamin A can be ingested in foods such as carrots.

Sjogren’s syndrome

Sjögren’s syndrome is a disease that affects the production of salivary and lacrimal glands.

It is an autoimmune disease that can lead to dryness of the mouth and eyes and, consequently, dry eye syndrome. Eventually it can also cause dryness of the skin and other organs, such as the intestines.

It is a rare disease, but it is considered the most common of rare diseases , affecting up to 2% of the world population.

Inflammatory diseases

Certain inflammatory and autoimmune diseases, such as lupus , can cause conjunctivitis , which in turn can lead to dry eyes.

Other inflammatory diseases can also cause this dryness.

Read more: Symptoms of lupus: how does autoimmune disease affect the body?


As we age, parts of our body can lose efficiency and the tear glands are no different.

Tear production drops by 65% ​​at 65 years of age when compared to the production we have at 18 years of age.

That is why aging can facilitate dry eyes and the syndrome affects up to 70% of those over 65 years of age.

Groups and risk factors

There are some conditions that increase a person’s chances of developing dry eye syndrome.

They may be due to genetic conditions, age-related problems or environmental conditions, such as too dry air.

The main groups and risk factors are:

  • Advanced age;
  • Women;
  • Frequent use of screens;
  • Contact lenses;
  • Pregnant women;
  • Smokers;
  • Asians;
  • Autoimmune diseases;
  • Inflammatory diseases;
  • Medication.

What are the symptoms of dry eye syndrome?

The symptoms of dry eye syndrome can present in different intensities, but in general they are:

Dry eyes

The classic and main symptom is dryness of the eyes, which occurs due to the accelerated evaporation of tears or reduced production of the tear glands.

This dryness is what leads to several other problems that can affect the patient’s eyes.

Sensitivity to light (photophobia)

The light can cause the eyes of the patient suffering from dry eye syndrome to become sore. This can bring difficulties for the person when leaving the house in the sun, for example.

This is because, without the protection of the tear layer, the light reaches the eyes directly.

Pain in the eyes

Even without light, dry eyes can cause pain in the eyes, which need lubrication and are irritated without it.

This pain is especially intense when there is wind, as without the protection of tears it may seem that there are pebbles being pressed against the eyes.

The truth is that very small objects, which normally do not come into contact with the eyes because of tears, can now do so.

Feeling of sand in the eyes

With dryness, small particles that would normally be suspended in tears can come into direct contact with the eyes.

This makes the patient feel that there are things there, which there is, but this time there is no protection. The sensation is usually described as if there is sand in the eyes.

Itchy eyes

Due to dryness, the eyes may itch.

This itchiness, besides being uncomfortable, can cause damage if the patient scratches too often, increasing irritation and allowing the contact of bacteria at a time when the region is without the usual protection from tears.

Eye redness

Without lubrication, the eyes become irritated and red, which can also be accentuated due to itching and contact with microbes.

Burning and burning sensation

Eye lubrication also protects the eyes from the damaging effects of heat and light.

Because of these actions, the patient may experience a burning sensation and burning in the eyes, especially when exposed to strong light.

Blurred vision

Lack of lubrication, over time, can cause vision damage, which can make it cloudy, making daily activities difficult, such as reading.

Reflex tears

When something enters the eyes, it is common for them to start to water in reflex. This can also happen when the eyes are irritated, which is common in patients with dry eye syndrome.

So, in some cases, lacrimation can be a symptom.

However, it is important to note that this type of tear is not the same one that usually lubricates the eyes, since its composition is different.

Dry eyes and dry mouth

There is a relationship between dry eyes and dry mouth.

One of the causes of dry eye syndrome is Sjögren’s syndrome. This syndrome causes both the lacrimal and salivary glands to produce less fluids (tears and saliva).

The result of this syndrome is that both the eyes and the mouth become dry, which can cause several problems for the patient.

Despite this, dry mouth is not directly related to dry eye syndrome.

Exams: how is the diagnosis made?

The diagnosis of dry eye syndrome is usually clinical. From the conversation with the patient and physical exams, the eye doctor is able to identify the condition.

However, it is possible that other tests will be done to assess the situation. For example:

Examination of slit lamp

The slit lamp is that classic eye examination in which the patient rests his chin and has his eye illuminated by focused light.

The ophthalmologist can then evaluate the tear filter , which is the lubricating layer of the eyes, through a microscope.

With these images, the doctor can have more details about the patient’s tear condition.

TBUT test

The TBUT test, or Tear Break-Up Time Test, is used to verify the time it takes the tear to break.

The tear film is a liquid layer that stays in the eye and lubricates it. This layer breaks down naturally after a few seconds, which dries out the eye.

The tear film is expected to last approximately 12 seconds before breaking. The frequency with which we blink guarantees lubrication, since we usually blink faster than that, renewing the tear.

However, when the tear composition is inadequate, the breakout time can be much shorter, which causes dry eyes to occur much faster.

This test identifies the tear film breaking speed.

Schirmer tests

The Schirmer test is performed to quantify the patient’s tear production.

For this, a marked filter paper tape is placed on the lower eyelids. The patient should close his eyes gently and stay that way for five minutes.

The tape absorbs tear liquids and stays moist as time goes by. The humidity can reach the marks that are at 5mm, 10mm and other distances.

When tear production is adequate for ocular lubrication, moisture is expected to reach the 10mm mark or more.

Between 5mm and 10mm, the eye is dry and below 5mm, the dryness is severe.

Can dry eye syndrome be cured?

It depends on the cause . Pregnancy, for example, eventually ends and eye lubrication returns to normal.

However, many of the conditions that cause dry eye syndrome are not curable, so neither is dry eye.

The causes are numerous and only with the help of the ophthalmologist can they be accurately identified and eliminated, when possible.

What is the treatment for dry eye syndrome?

Although, in many cases, dry eye syndrome is not curable, there are treatments for symptom relief. Are they:

Artificial tears (lubricating eye drops)

Artificial tears, or lubricating eye drops, serve to lubricate the eyes when the body itself is unable to do so properly.

It is a product indicated when the patient has mild or moderate dryness of the eyes. In these cases, artificial tears are often the only treatment applied directly to the eyes until the cause is eliminated.

This product may be essential for the patient with dry eye syndrome, as it replaces the missing lubrication and eliminates the symptoms of the condition.

The formulations of artificial tears can be varied, which changes the viscosity of the substance.

Your eye doctor can help you choose which one is right for you, depending on your needs.

The more viscous formulations last longer, but tend to blur the vision, while the more liquid formulations leave the vision clear, but may need frequent reapplication.

Each moment of the day may require a different type of artificial tear.

Plug lacrimal

The eyes have channels through which tears enter and channels through which they drain, thus preventing tear accumulation.

A possible treatment involves a plug in the tears drainage channels.

The plug is made of collagen (in the case of temporary) and silicone (in the case of permanent).

The temporary plugs are absorbed by the body after some time and are mainly used to test whether the blockage of the canal will not cause excess tears.

The permanent plugs need to be removed, if necessary. They can also fall in some situations.

The plugs reduce the amount of tears that leave the eyes, allowing them to lubricate the area for longer.

Surgery of the salivary glands

One possible surgery to deal with dry eye syndrome involves connecting the salivary glands to the tear ducts. Thus, saliva lubricates both the mouth and the eyes.

This surgery is not a solution if the cause of the dry eye syndrome is Sjögren’s syndrome, as it causes the salivary glands to dry out as well.

Eye drops for dry eye

There are a few options for dry eye syndrome, but they vary depending on the cause of the condition.

In general, the indication is to use eye lubricants, or artificial tears, to replenish the hydration of the eyes.

Eye drops with medications can also be an option when there is an underlying cause. That is, they serve to address the source of the problem.

It is important that the patient uses the correct type of eye drops, as one type acts differently from the other. For example, some are vasoconstrictors, which eliminates eye redness, but when the effect wears off, dryness gets worse.

Therefore, it is important to consult the ophthalmologist.

Lubricating eye drops

Lubricating eye drops are great allies for people with dry eye syndrome, replacing natural eye lubrication with a synthetic one over which the patient has control.

An example is the Systane UL ophthalmic lubricant , a product designed for the symptoms of dry eye.

The composition is similar to natural human tears and its application gives comfort, relief from itching and protects the eyes with a protective and lubricating layer.

With the use of lubricant, the tear film is reconstructed, giving the natural sensation of well-lubricated and protected eyes.

Its application must be made whenever necessary or according to the ophthalmologist’s instructions.

In general, 2 drops in each eye for each application ensure eye lubrication, eliminating the symptoms of dry eye.

Anti-inflammatory eye drops (immunosuppressants)

Immunosuppressants are drugs that reduce the capacity of the immune system, making it less active.

While in most cases this seems like a bad idea, this is the treatment used against autoimmune diseases , in which the patient’s immune system attacks the body itself.

Certain autoimmune diseases can cause dry eye syndrome, such as lupus.

Therefore, in these cases, immunosuppressants can be used to reduce the symptoms of both conditions. Among the options is Dexamethasone ( Decadron , Maxidex ).

It is worth remembering that these drugs require a medical prescription.

Read more: What are the options for antiallergic eye drops?


NEVER self-medicate or stop using a medication without first consulting a doctor. Only he will be able to tell which medication, dosage and duration of treatment is the most suitable for his specific case. The information contained in this website is only intended to inform, not in any way intended to replace the guidance of a specialist or serve as a recommendation for any type of treatment. Always follow the instructions on the package insert and, if symptoms persist, seek medical or pharmaceutical advice.

Home treatments

There are some treatments that can be done at home to relieve symptoms.

They are not meant to cure dry eye syndrome, so it is important to have a follow-up by the ophthalmologist , but reduction of irritation, redness and itching can be achieved.

It is important to remember that nothing should be dripped into the eye .

The medications indicated by the doctor are the only ones that must be applied intraocularly. Other substances can cause infections, burns and even blindness.


The use of cold compresses can be indicated for the relief of symptoms and does not present risks to the eyes, as long as they are not applied inside them.

Ophthalmologist Dr. Michel Rubin points out that despite having a positive effect, this is not a solution.

“ The cold compress or chamomile tea, which is more neutral, can be applied without a problem, but you are giving temporary relief, not treating the cause. It is very important that you investigate the cause ”, he says.

Omega 3

Omega 3 is a substance found in certain foods and dietary supplements. There is evidence that this substance may benefit those with evaporative dry eye syndrome, as it can help improve the quality of tears.

Recent studies indicate that the effects of omega 3 for dry eye syndrome are not as significant as previously believed, but they still exist.

“ As it has several benefits for skin, hair, nails, I don’t see any problem as an adjuvant treatment, but [omega 3’s] performance is modest ”, says Dr. Rubin.

So, remember that using omega 3 is an aid in the treatment, but it will not cure you of the condition. Consulting an ophthalmologist is indicated and the best way to deal with any disease related to the eyes.

Tips for Relieving Dry Eye Symptoms

In cases where the dry eyes are chronic, the patient must remember to use the lubricating eye drops in the manner indicated by the ophthalmologist.

In addition, it is important to visit the doctor frequently to assess the condition of the eyes. Other tips include:

Choose the right eye drops

Eye drops are very important for patients with dry eye syndrome. Remember to follow your doctor’s advice as not all eye drops are necessarily lubricants.

Some contain antibiotics , others are anti-inflammatory and there are also those with vasoconstrictor action (which do not lubricate).

Depending on the cause of your condition, you may need one or the other, but using the wrong type can cause problems.

In the case of antibiotics or anti-inflammatory drugs, it is necessary to follow the doctor’s instructions so that there are no problems such as the creation of a superbug due to improper use.

When your eye drops are a lubricant, you can use it whenever you feel the need to lubricate your eyes.

Protect your eyes

When your eyes are dry, they are more vulnerable to the environment. Bright light, wind, dust and other factors can cause visual damage that does not normally affect people with intact tear film.

Wear eye protection. Dark glasses can be indicated to protect you from light and wind.

Do not dive in pools full of chlorine without goggles and do not forget the visor of the motorcycle helmet.

Take care of hygiene

Remember to take good care of your eye hygiene to avoid contact with bacteria and eye irritation.

Remove all makeup and do not scratch your eyes , as this can worsen symptoms and bring dirt and bacteria to them.

Evaluate the use of contact lenses

Wearing contact lenses is one of the possible causes of dry eye syndrome. Assess, with the guidance of an ophthalmologist, whether it is not possible to switch to glasses, which can reduce the chances of infection and irritation.

If you plan to continue wearing contact lenses, always keep them clean and well looked after.

Can I use eye drops with contact lenses?

Yes , you can. However, it is important to find out if the eye drops are suitable for use with lenses. Eye drops with preservatives can, over time, damage contact lenses, so they are not recommended.

There are preservatives that are designed for use with lenses and in that case, there is no problem using them with lenses.

If you use eye drops with preservatives that are not suitable for lenses, it is recommended to remove them before application, which prevents damage.


The prognosis is usually positive when the condition that causes dry eye syndrome is identified and treated early, often resulting in recovery from normal tearing.

However, in cases where the syndrome is chronic, treatment with artificial tears can be permanent to avoid possible damage to the cornea due to dryness and direct contact with the eye with dust, sand, wind or bacteria.


When dry eye syndrome or its cause is not treated, complications can occur, the main one being reduced vision.

Corneal scratches

One of the main functions of tears is to create a protective layer for the eyes, which normally should not come into direct contact with dust or other particles that may be in the air, as well as bacteria.

When the eyes are dry, these particles can cause scratches on the cornea (membrane that acts as the lens of the eye), which in turn can reduce the patient’s vision, in addition to causing a lot of pain, irritation and itching.

The loss of vision due to dryness worsens with time without treatment.


As one of the functions of tears is to protect the eyes from bacteria, when there is less tear lubrication, they are more vulnerable to possible infections that can reach them.

Corneal vascularization

The cornea, which is the lens of the eyes, is not a region with vascularity, which means that there are no veins or arteries in it.

When dry eye syndrome is severe, blood veins may appear in the structure of the eye.

According to the ophthalmologist Dr. Michel Rubin, ” patients with severe dry eye can evolve even with corneal vascularization, which damages and can even cause perforation of the cornea with loss of vision “.

How to prevent dry eye syndrome?

Although 70% of the elderly have dry eye syndrome, which indicates that most people will eventually have the condition to some degree, there are actions that can be taken to prevent the syndrome for longer, or entirely. Are they:

Avoid air conditioning

Air conditioning tends to leave the environment dry, which facilitates the evaporation of tears, causing dry eyes.

It is also important to remember not to stay too long in very dry environments.

Pause screens

Cell phone, computer, tablet … The screens make you blink less, which also impairs the lubrication of your eyes. You can take hourly breaks.

Take a walk, rest your eyes, look at distant things (this helps get your eyes used to focusing on distant objects, unlike screens), and make sure you blink to lubricate your corneas well.


Although they are not only composed of water, this is the main raw material for tears.

Remember to stay hydrated. It is the best way to ensure that your eyes will be well lubricated.

Stay away from the cigarette

Smoking brings smoke to the eyes, which helps with dryness, in addition to causing irritation and itching, which can also trigger a dry eye syndrome. Avoid smoking.

Cigarettes are bad for your vision in more ways than one, and can cause many other problems.

It is also relevant that passive smokers take care and try to stay away from the smoke. Even if you don’t smoke, a smoker’s smoke can get in your eyes and cause irritation.

Avoid scratching your eyes

If you have itchy eyes, use eye drops or go to an ophthalmologist, but avoid scratching them directly as this can lead to bacteria in them, as well as causing dry eye syndrome.

Dry eye syndrome in dogs

Dogs are often affected by dry eye syndrome.

The condition is especially common in some breeds, such as Pugs and Yorkshires, but it can also affect the Boston Terrier, Cocker Spaniel, Pekingese, Shih Tzu, Schnauzers, Lhasa Apsos, among others.

In the case of dogs, viruses or intoxication are common causes, in addition to the same factors that can affect humans.

Treatment for dogs is similar to human treatment.

First, it seeks to combat the cause. If this is not possible, artificial tears can be used, in addition to the tear plugs and surgery to connect the salivary gland to the tear ducts.

Dry eye syndrome can range from discomfort to serious vision problems. It is important to keep your eyes lubricated.

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