It sounds counter-intuitive, but tearing is one of the more common symptoms of dry eye.
The tearing is “reflex” tearing and occurs in response to your eye being irritated due to dryness, or getting poked in the eye.
Dry eye syndrome, also known as keratoconjunctivitis sicca, is very common and affects over 300 million people around the world. Dry eye is probably the most common reason for a visit to the eye doctor.
Symptoms of Dry Eye
With every blink, tears are evenly spread across the surface of your eye. Tears help fight infection and also keep your cornea hydrated, smooth and clear.
The cornea is exquisitely sensitive. If you have ever scratched your cornea, you know how sensitive and painful your eye can become.
The cornea is also responsible for about 2/3 of the overall focusing power of your eye. Any change to the cornea can translate into blurry vision.
Common Symptoms of Dry Eye;
- Tearing and redness
- A dry sensation
- Blurry vision
Normal Tear Film
Your tears are actually a 3 layered film. On the surface of your tear film is an oily layer which prevents evaporation.
The middle layer is the watery part and the bottom layer, called the mucin layer, ensures that the tears are spread evenly across the eye.
The oily layer is produced by Meibomian glands located on the edges of your lids. The actual tears are produced by the lacrimal gland – there is one lacrimal gland for each eye.
The bottom mucous layer is produced by special cells located in the conjunctiva – the clear tissue on the outside of your eye.
Causes of Dry Eye
If you search “dry eye,” you will find dozens of causes of dry eye, but in reality there are just two basic mechanisms, either of which can be caused by any one of the “causes.”
- Insufficient tear production
- Rapid evaporation