Is it Quantity or Quality of Tears that cause Dry Eye symptoms?
W
ell, it depends.
We often think when our eyes are dry, it is because we don't have enough moisture or tears to lubricate the ocular surface. But the problem may actually be the
quality
of tears you are producing
.
If the tears evaporate too quickly or do not spread evenly over the cornea due to deficiencies with any of the three tear layers, dry eye symptoms can develop. The three layers that make up the tear layer are:
- Oil Layer: this layer maintains tears on the surface of the eye and avoid evaporation.
- Aqueous Layer: this is the watery layer that contains water and proteins and makes up the majority of the tear volume and is responsible for tear spreading.
- Mucous Layer: this layer acts as an anchor to hold the tear film to the eye.