Types of Dry Eyes

What are the types of Dry Eyes?

There are two main types of dry eyes and this includes:

  • ADDE: Aqueous Deficient Dry Eyes – which is simply defined as a reduction in the production of tears.
  • EDE: Evaporative Dry Eyes – which is the loss of tears from the surface of the eye when there is normal production of tears.

Although, dry eyes are broadly classified into these two categories, they are not mutually exclusive and you can have a combination of the two.

What causes Dry Eyes?

A number of factors contribute to dry eyes, this can include:

  • Age: As we age, the flow and production of tears reduces. This coupled with changes in the composition of our tears can increase our risk and contribute to dry eye symptoms.
  • Gender: Our hormones can play a part in affecting our eyes and it has been found that females tend to be at high risk of developing dry eyes.
  • Environment: Studies have found that environments of low humidity (ie. air conditioning & air travel) and high wind velocity (ie. windy days) can contribute to dry eyes.
  • Medications: Some medications can include side effects that can cause dry eyes. For example: antihistamines, beta blockers & diuretics. Treatment for eye conditions using long term eye drops can also contribute to dry eye symptoms.
  • Screen Use: Computer/tablet/phones/laptops are now a part of daily life, however, it has been demonstrated clinically that when we use our screens we blink less and this can contribute to dry eye.
  • Ocular Conditions: Other eye conditions like blepharitis can contribute to dry eye symptoms.
  • Systemic Conditions: Certain systemic conditions can cause dry eyes. For example: diabetics may be more prone to developing dry eyes.
  • Contact Lens Use: Chronic contact lens use can reduce the stability of the tear layer which can cause dry eyes.
  • Refractive Surgery: Refractive surgery can exacerbate pre-existing dry eyes or trigger borderline dry eye patients. It is important that prior to refractive surgery your dry eyes in managed so as to reduce post operative symptoms.