Blepharitis occurs when something (usually chronic inflammation) causes the meibomian glands become clogged. Less oil is contributed to the tear film, meaning that the tear film evaporates more rapidly, rendering the surface of the eye drier.

When any fluid evaporates, it reduces the temperature of the surface it was on very slightly – and the cornea actually has nerves that can detect these small temperature changes. What happens next is that your body responds by telling the lacrimal gland to produce more tear fluid. This means, paradoxically, that you can have “watering” eyes because of dry eye!

Blepharitis explained

Stages of Blepharitis

In early stages, “plugs” appear on the edge of the eyelid which block the openings of the sebaceous glands. In this case, a simple mechanical cleaning can be effective.

However, if the inflammation of the eyelid margin is not treated for years, the eyelid will change anatomically. The edge of the eyelid becomes increasingly rounded and is no longer able to distribute the tear film on the surface of the eye, similar to a windscreen wiper with gaps on the Windshield.

More and more symptoms like burning and biting and also blurred vision will develop

Rare reasons for a dry eye

In addition, systemic diseases such as psoriasis (rosacea), diabetes, polyarthritis, lupus erythematosus and Sjögren syndrome can cause dry eyes. Hormonal changes (such as those caused by hormone replacement therapy during menopause and contraceptive pills) are also a potential cause of dry eye syndrome. Other chronic inflammatory diseases like Crohn’s disease and ulcerative colitis can lead to a dry eye, because of the strong diarrhea and nutrient malabsorption.

Quality of life

Dry eye is not an immediate danger to vision  – almost nobody will go blind thanks to it. But in most cases, it degrades people’s quality of life, often greatly.

The symptoms in the dry eye are varied and range from mild to massive: eye burning and biting, blurred vision, double vision, and headache, and unfortunately a lot of modern life can exacerbate this, as these symptoms typically occur more frequently after prolonged computer work, television viewing, and reading (be it a tablet, smartphone, or even an old-fashioned book).

TV interview on the causes of dry eye

Office-based professionals and contact lens wearers

One of the most common reasons for people to visit an ophthalmologist is for dry eye treatment. Many professionals sit in front of computer screens for most of their working day. Most office spaces have air conditioning. Screen use decreases your rate at which you blink; air conditioning dehydrates you. Either circumstance can cause dry eyes; but the combination really increases the chances of you having “Dry Eye Syndrome” (DES). Sometimes it’s called “Computer Vision Syndrome”, “Office Eye”, or is just described as “tired eyes”.

Contact lens wearers often develop DES after a few years of wearing the lenses (especially soft contact lenses), and shift workers and night workers commonly develop DES, as tear film production (the natural lubricant of the eye) is affected by circadian (day/night) rhythms – at night, less tear film is produced. Finally, tear film production decreases as people age, to the point that a significant proportion of people aged 65 years or older have DES (although people of all ages can be affected).

The good news is that your dry eyes can be treated – and there’s more that can be done that just offering lubricating eyedrops.

In Switzerland, it’s reported that 600,000 people have been officially diagnosed with DES – but it’s likely that the true number is much higher thanks to unreported cases – people who live with DES, but haven’t asked for help.

Contact Lenses

Night Work

Dry eyes generally affect people of all ages, with an accumulation of the following populations:

  • Contact lens wearers (especially in wearers of soft contact lenses)
  • Professionals who work a lot on computers and / or are often in air-conditioned rooms
  • Older people (> 65 years)
  • Night workers / shiftworkers, as tear production is closely linked to the day-night rhythm.

The ELZA Institute