What causes dry eyes?
The tear film is made up of 3 main layers;
- A mucous layer that acts like glue to stick the tears onto the eye
- The main watery layer that is full of nutrients for hydrating and keeping the surface of the eye healthy
- The oil layer on the top to make sure that the watery layer does not evaporate or dry up in the wind
You need all three layers to be present for the eye to feel comfortable, and the layers need to be in the right balance. Dry eyes are caused when the tear film isn’t the right composition, or the volume isn’t correct. This prevents the tear film from performing its important roles.
Tear Film Instability and Hyperosmolarity are two important terms found frequently in academic literature, as dry eye syndrome is referred to as a cycle that requires ongoing care.
Tear Film Instability is the term used to describe poorly balanced tear film layers. This usually occurs when glands or structures responsible for producing those tear layers are damaged or irritated. Without all three tear film layers performing properly, the tears do not have the right balance of saltiness and cannot effectively hydrate and nourish the eye. This is referred to as having hyperosmolar tears.
Hyperosmolar tears occurs when the balance isn’t right. This causes irritation to the eye surface and can damage the structures that produce the layers in our tears. This results in more “tear film instability!” This is the vicious cycle of Dry Eye.
There are many environmental and lifestyle factors, as well as medical conditions and medications, that can affect the production of the three important tear layers.
What does dry eye feel like?
Everyone experiences dryness differently. Symptoms can include tired, scratchy, sandy, sore, red, burny, itchy or irritable eyes. The eyelid margins may become red, swollen and inflamed. Your vision can also fluctuate with blinking. Confusingly, dryness may also lead to watery eyes. Dry eyes may have crusty buildup/discharge when you wake up, causing the eyes to feel stuck together. The true underlying cause of all of these symptoms is a poor quality tear film.
Please contact us to arrange a dry eye assessment appointment along with your comprehensive eye & vision examination.