Dry eye syndrome: burning and tired eyes? Causes and symptoms

Do your eyes have sand in them, do they burn and cut you, or do you see blurry?

Maybe you suffer from dry eye syndrome.

The term dry eye, also called keratoconjunctivitis sicca, was coined by the Swedish ophthalmologist Henrik Samuel Conrad Sjögren as early as 1933.

Dry eye nowadays affects approximately 20% of the population and 30% of menopausal women.

The eyes need a sufficiently and well moisturised surface for their normal function. The tear film, i.e. the tears, serves this purpose. Moisturising is provided by the eyelids when blinking.

Tears are not just water, a fluid without substances. Their importance is too great and irreplaceable for the normal function of the eye and vision.

What is tear film (tears)?

Tears are mostly made up of water, and 99 percent of them are water. The other percentage is divided for substances such as salts, proteins and organic matter, glucose, amino acids, and exfoliated parts of the epithelium.

The unique chemical composition ensures an antibacterial effect. It kills bacteria on the surface, around the eye and in the conjunctival sac. Tears are constantly formed and secreted throughout the day. Their production is reduced only during sleep.

The tear film is located on the outer surface of the eye. In addition to protecting the cornea and conjunctiva from drying out, it is important in nourishing and oxygenating parts of the eye.

The main importance of the tear film for the eye:

• mechanical barrier
• antibacterial protection
• leaching of contaminants
• has optical properties
• nourishment
• oxygenation

The tear film is composed of three layers. Each of them has its own meaning.

Table: layers of the tear film and their importance for the eye

What is the definition of dry eye syndrome?

Dry eye is defined as a failure to wash the ocular surface, the cause of which is a defect in the tear film. The damage is caused by a change in the composition, formation or flow - distribution of the tear film.

It can be referred to as qualitative or quantitative error.

Qualitative means that it is caused by a change in the content of the tear film, even with preserved tear production. Quantitative indicates that there is insufficient quantity.

The consequence is a reduced supply of nutrients and oxygen, but also a lack of protection from the external environment, bacteria. The tear film is disturbed, the eye dries out faster. This leads to the formation of scars or corneal opacities.

The risk is the development of severe defects on the surface of the cornea, deterioration of vision and, in extreme cases, blindness.

What causes dry eye syndrome?

The cause of dry eye is basically a failure to wash the ocular surface, which results in an insufficient composition or quantity of the tear film.

The problem can also arise as a result of associated abnormalities of the eyelid, which causes damage to the surface layer of the eye - the cornea - when blinking.

The tear film can be disrupted by a variety of mechanisms that cause it to become incoherent and unstable.

Table: distribution of tear film disorders by location

As is clear from the table, disruption of the tear film can occur in any part of it. Different factors are involved in the formation.

Factors influencing the development of dry eye:

• age, when both the production and the quality of the tear film decreases, plus associated general diseases 
• hormonal influence, especially in women during menopause or when androgens decline
• general diseases such as diabetes, hypertension, rheumatoid arthritis
• chronic inflammations of the eye such as Sjörgen's syndrome, allergic inflammations, trachoma
• medicines such as diuretics (urinary medicines), beta-blockers, benzodiazepines, antidepressants, antihistamines, cytostatics
• eye drops, with prolonged and reckless application of eye drops
• eye injuries
• systemic diseases, lupus, scleroderma
• wearing contact lenses
• bathing in chlorinated water
• eye surgery, e.g. also after laser eye surgery
• external factors, faster evaporation of tears or insufficient blinking
  • dry environment
  • air-conditioned spaces at home, in the workplace in the car
  • working in draughts and wind
  • looking at a monitor, mobile phone or TV
  • prolonged reading

These factors are cited as the main factors in the occurrence. However, we also know of some co-factors that exacerbate the difficulties.

What aggravates dry eye syndrome:

• reduced fluid intake
• vitamin A and omega-3 fatty acid deficiency
• dry air in the room
• frosty and dry weather
• use of air conditioning, especially blowing directly on the face
• heating during the heating season
• draughty and windy weather
• intense lighting
• working behind a monitor for long periods of time, looking at your mobile phone or TV for long periods of time
• also referred to as office eye syndrome
  • poor monitor placement
  • reduced blinking frequency when concentrating on the content seen and exaggerated accommodation
  • long reading, but also driving
• stress, psychological and emotional burden
• dust and air pollution
• smoking, especially in smoky and smoky areas
• excessive use of alcohol, caffeine
• insufficient eye protection when swimming, cycling, working
• frequent rubbing of the eyes
• use of contact lenses
• seasonal allergies

Learn more:
Health effects of air conditioning
How to use air conditioning properly without harming your health

Dry eye syndrome affects both eyes. Its manifestations are the familiar burning, itching, scratching or redness of the eyes. To make matters worse, this problem is also accompanied by other difficulties.

What difficulties can a person complain of with this syndrome:

1. dry eye sensation
2. sensation of a foreign object in the eye, as if sand in the eyes
3. burning, itching, scratching in the eyes
4. pressure in the eyes and eye pain
5. increased sensitivity to light, so-called photophobia, or painful perception of light
6. staying in a dusty, smoky or air-conditioned area is a problem
   • when difficulties worsen
   • even in windy weather
7. eye fatigue, strain
   • faster fatigue when working at the computer
   • inability to work longer
8. sensation of heavy eyes
9. swelling of the eyelids
10. redness due to increased blood supply to the conjunctiva
11. accentuation of the vessels of the white of the eye
12. excessive tearing, in some cases
13. blurred and hazy vision

As indicated, the difficulty may stem from a different place. Accordingly, some difficulties outweigh others. 

Damaged mucin layer

If this layer is disturbed, significant tearing occurs, which is why it is also referred to as dry wet eye. Tears are formed at a normal rate, however, due to mucin damage they do not bind sufficiently and run off the surface of the eye.

If the aqueous layer is damaged

The sensation of a dry eye, a foreign body in the eye - sand or cutting - comes to the fore.

Exacerbation of the discomfort occurs especially in the evening. Also with long work at the monitor, watching TV, reading for a long time. The problem also makes the transition and stay in air-conditioned space.

When the lipid layer is damaged

This form results in increased evaporation of the aqueous component of the tear film.

The most serious difficulties are especially in the morning after waking up. The sufferer has a feeling of difficulty opening the eyes, sticking eyelashes, eyelids. Stinging pains are a harbinger of defects on the surface of the cornea.

Diagnosis is based on the medical history, and therefore the subjective difficulties of the person. These can indicate to some extent which form of impairment is involved.

Other long-term illnesses, allergies or recent injuries are also detected in the medical history, including medication taken and the occupation.

In addition to the medical history, other examinations are also carried out. Examination of the anterior segment of the eye, a test to examine the tear film.

A so-called slit lamp is used, with the help of which the cornea, conjunctiva is examined.

The examination of the anterior segment of the eye uses:

• staining of the surface of the eye, which reveals defects on the surface of the eye
• Lipcoff's lid-parallel conjunctival folds (LIPCOF) 

The quality and quantity of tears are assessed. Examples of tear film tests are the Schirmer's tear film break up time test, i.e. the time it takes for the tear film to break up, also referred to as BUT, or Break Up Time. Another test is the tear film recovery test.

Differential diagnosis and detection of the true cause or other eye problem, such as allergies, is important. On the basis of the examination, the doctor then selects the appropriate course of treatment.

In dry eye, there are mainly symptoms such as eye fatigue, a feeling of vague discomfort. Redness, burning, cutting or itching of the eyes are also associated.

Do I have sand in my eye, burning and cutting me?
My eyes are dropping from fatigue, I can't work at the computer anymore.

The world is all blurry to me.

Sometimes the difficulties are more pronounced first thing in the morning or, on the contrary, only after prolonged work at the computer. Increased tearing may be present. These difficulties may lead to suspicion of damage to the lipid, lacrimal or mucous layer.

In the subsequent period, other difficulties are also associated, an example being blurred and hazy vision. Going into areas with intense lighting or air-conditioned rooms, such as shopping malls, is problematic.

Will self-medication help me?

We can make our difficulties worse by inappropriate self-medication.

Therefore, it is important to be examined by an eye doctor, or ophthalmologist. Based on the subjective difficulties and a thorough diagnosis, the ophthalmologist will determine the correct and appropriate course of action.

Let's not forget the regimen for dry eye syndrome

Let's not forget about safety measures and eye protection.

Watching too much TV for too long has a negative effect. Movement in the fresh air will be better. It is important to protect your eyes when working behind a monitor for long periods of time.

Glasses with a suitable filter are helpful.

Similarly, special protective glasses will help in specific conditions. It is important to avoid staying in a risky area - smoky or air-conditioned.

The eyes need sufficient sleep and rest. When reading or watching monitors and television for long periods of time, it is advisable to briefly avert your eyes to a distance - away from the content you are watching.

Avoiding stress will help, but so will changing your lifestyle, supplementing vitamins and drinking enough. Eyelid hygiene is important.

Positively influencing regime measures:

• drinking lots of fluid
• higher humidity and other microclimate modification
• protect your eyesight
  • limiting television viewing or long reading in poor lighting
• thorough treatment of long-term diseases
• effective lubrication - moistening with eye lubricants, artificial tears
• limiting preservatives and phosphates that disrupt the tear film
  • unnecessary application of eye drops, which only aggravate the condition in the long term
• regular ventilation