Your tears are composed of 3 layers – oil, water and mucous. The oily layer is produced by the meibomian glands. Which line the edge of the eyelids.
Which sits just below the eyebrow produces the watery layer. The third layer comes from microscopic goblet cells in the conjunctiva.
To keep your eyes comfortable, a small volume of tears is continually produced. When your eyes are irritated or when you cry, a greater volume of tears are produced from larger glands near the outer corner of the eye.
Some of the fluid in the tear evaporates from the surface of the eye. The rest drains from the upper and lower eyelids near the nose through bony canals (known as nasolacrimal ducts or tear ducts) and into the nose. This is the reason you need to blow your nose when you cry!
This image shows the parts of the eye associated with tear production and drainage.
The main reasons for watery eye problems are:
- overproduction of tears (too many)
- poor drainage of tears
- a combination of both.
Too many tears
Overproduction of tears is usually due to irritation or inflammation of the surface of the eye. There are many potential causes but the commonest include:
- eyelid inflammation (blepharitis) or สนใจสมัคร? คลิกที่นี่เพื่อเริ่มต้น eyelid problems – where they turn inward (entropion) or outwards (ectropion)
- eyelash problems
- dry eye – if the surface of your eye is dry your body produces more tears to try and lubricate it
- allergies, eg, hay fever
- irritation from being in an environment that’s cold, windy or has very strong light.
Note that some overproduction of tears can be expected. When you’re in the wind or you get something in your eye, but constant watering isn’t normal and should look into.
Treatment of tear overproduction involves identifying and relieving the cause. The treatments are usually non-surgical and may need to continue in the long term to control the underlying problem. Treatment could include antihistamines, antibiotics, warm compresses or massage if the excessive tears are due to an infection or an allergy.
Poor tear drainage
Again, there are many potential causes for poor or reduced tear drainage. These include:
- looseness of the lower eyelids causing the drainage system to fail
- narrow or displaced tear drainage openings.
- partial or complete blockage of the nasolacrimal duct (the bony canal that drains tears from the eyes).
Treatment of poor tear drainage is usually surgical. This may include
- eyelid tightening
- opening of the puncta (tear drainage openings)
- surgery to remove an obstruction.
Surgery usually works well in improving watering problems due to poor tear drainage.