What is ‘Dry Eye Disease’?

The tears that your eyes normally produce are necessary for clear vision and maintaining eye health. Dry eye occurs when your eyes do not produce enough tears, or more commonly, produce tears that do not have the proper chemical composition.

What is ‘Dry Eye Disease’?
  • Normal ageing processes
  • Side effects from some medication e.g. anti-histamines, anti-depressants etc
  • Hormonal changes
  • Environmental conditions e.g. hot, windy climates, heated offices etc
  • Certain general health issues/ chronic diseases e.g. rheumatoid arthritis
The tear film

The tear film is a complex structure which consists of three key layers:

  1. Mucous layer
    A very thin layer of mucous is secreted by cells distributed across the eyes surface. It forms a sticky base layer, holding the tears against the eyes surface.
  2. Watery layer
    The watery layer is the main body of the tears. It contains nutrients and essential proteins and is made by the lacrimal gland. When the larcrimal gland is stimulated from pain or wind or emotions, the eye may become watery.
  3. Oily layer
    A thin oily layer, keeps the tear surface smooth and prevents evaporation of the watery layer. It is produced by rows of meibomian glands, running vertically in the upper and lower eyelids and opening just behind the roots of the lashes.

The tear film is spread across the surface of the eye by the eyelids when you blink, and drains into the tear ducts (situated in the corner of the upper and lower lids) and then into the nose.

What are the symptoms of dry eye disease?
  • Dry, sore eyes
  • Itchiness and scratchiness
  • The feeling of something being in your eye (foreign body sensation)
  • Burning, stinging, gritty feeling
  • Watering – this is a natural reflex the body produces to comfort a dry eye but is unusually ineffective in stopping the symptoms
How is dry eye disease diagnosed?

During an Anterior Eye Examination, your optician will ask you questions about your general health and medications and your home & work environments to determine any factors that may be causing dry eye symptoms. The practitioner will then perform specific dry eye tests using special diagnostic equipment which allow a detailed, highly magnified view of the anterior parts of the eye. This is painless and will enable the optician to evaluate the quality, quantity and distribution of tears as well as the health of the eye lids, tear ducts, conjunctiva and cornea of your eyes and so be able to advise a course of treatment.

Will dry eye disease harm my eyes?

If dry eye is left untreated, it can harm your eyes. Excessive dry eye can damage tissues and possibly scar the cornea leading to impaired vision.

Dry eye can make contact lens wear more difficult due to increased irritation and poses a greater risk of eye infection.

To keep dry eye symptoms in check, follow your optician’s instructions carefully and if you suffer with any increase in dryness or redness that isn’t relieved by the prescribed treatment then book in for a follow up appointment.