Dry eyes can be caused or exacerbated by multiple underlying genetic, medical and health factors, including:
- Natural Ageing
- Meibomian gland dysfunction
- Autoimmune disorders like Sjögren's syndrome, rheumatoid arthritis, lupus, hypothyroidism, and Graves’ disease
- Blepharitis (inflammation of the eyelids)
- Facial palsy (which often prevents the patient from blinking or closing one or more eyes, leading to them drying out)
- Hormonal changes experienced during pregnancy and post menopause
- Your diet
- Medications such as antihistamines, antidepressants, oral contraceptives and some heart medications
- Excessive contact lens wear
- LASIK Surgery
- Stem cell transplant
- Certain drugs used in cancer treatments
- Allergies including hay fever
Dry eye through normal ageing
The most common cause of severe dry eye is the normal ageing process. Over time, your body produces less oil – 60% less at age 65 than at age 18. With less oil to seal the watery layer, the tear film evaporates much faster, leaving eyes feeling dry, gritty, and irritated. According to some estimates, as many as 75% of people over age 65 will experience severe dry eye.
Meibomian gland dysfunction
Eye specialists are increasingly aware of the role of the meibomian glands in many instances of dry eye, and are shifting emphasis away from long held assumptions that dry eye conditions are inflammation-driven.
Meibomian gland dysfunction (MGD) is now considered the leading cause of dry eyes. The meibomian glands, which are located within the eyelid near the lashes, are responsible for secreting the oily (lipid) layer in your tears. It is this layer that plays a critical role in preventing evaporation of moisture from your eyes.
If the meibomian glands are not functioning properly, your tear layer will be unstable and you will suffer from evaporative dry eye.
Excessive contact lens wear
People who wear contact lenses have an increased risk of developing Dry Eye Syndrome, as contact lenses absorb the tear film and increase the evaporation of tears.
Diseases such as Sjogren’s syndrome
Certain diseases and medications can lead to severe dry eye. For example, Sjogren’s syndrome is a chronic, autoimmune disease characterized by dry eyes, dry mouth and arthritis. Many other diseases such as rheumatoid arthritis, lupus, scleroderma and thyroid disease can also cause severe dry eye.
Genetic factors also affect a person’s susceptibility to dry eyes. Certain groups of people are at higher risk than others, including women, and individuals from Asian or Hispanic descent.