Normally, the eye constantly bathes itself in tears. The tear film is very essential for lubricating the ocular surface and protecting it by washing away harmful substances. These tears are produced at a slow and steady rate without our realization, called as basic tears. The tears that are produced on emotions or in irritated eyes are different in composition and are called reflex tears.
Tear film lubricates and protects the eyes, reducing the risk of eye infection. With each blink, the eyelid spreads the tear film evenly across the eye surface and clears the debris out of the eyes. Excess tears flow out through the drainage ducts located in the corner of the eye. These ducts lead to tiny canals that connect to the nasal passage.
|Inner Mucous or Mucin Layer||
Coats the cornea and helps the tear film to adhere to the eye. Produced by the goblet cells of the conjunctiva.
|Middle Watery or Lacrimal Layer||
Provides moisture and supplies important nutrients to the cornea. Produced by the lacrimal gland.
|Outer Oil or Lipid Layer||
|The oily film that blinds the tear film on the eye and prevents evaporation. Produced by the Meibomian glands.|
Sometimes people do not produce appropriate quality or quantity of tears. This condition is called as dry eyes.
Symptoms of DRY EYES:
- Stinging or burning eyes
- Stringy mucus in or around the eyes
- Excessive eye irritation from smoke or wind
- Excess tearing (reflex tearing due to irritation)
- Discomfort when wearing contact lenses
Causes of Dry Eyes
- Tear production decreases as we age
- Women are more commonly affected, especially after menopause because of hormonal changes. Men are also affected, but less frequently
- Environmental pollution, dust, wind and dry climates contribute to dryness in eyes
- Meibomitis or Blepharitis leads to poor quantity and quality of natural tears
- Staring continuously at the computer monitor results in reduction of the normal blinking rate causing the tear film on the surface of the eyes to evaporate
- Air Conditioning in the room further aggravate the dryness due to dehumidification
- Dry Eyes are commonly seen in patients of arthritis and people with dry mouth
- Prolonged use of Contact lenses also leads to dry eyes
- A wide variety of drugs like antihypertensive, (for blood pressure), anti histaminic (for cold), antacids (for acidity) and anti depressants can cause a drop in tear production. Preservatives in certain eye drops can also lead to dry eyes when uses over a long time
Eye drops called as artificial tears, which are similar in composition to our own tears are prescribed as replacement.
When tear supplements are to be used for a long time, it is better to use eye drops without preservatives. Since these drops do not have any significant side effects, they can be used frequently depending upon the symptoms of the patient.
Recently cyclosporine eye drops have been advocated for increasing the basic tear production.
People with dry eyes should maintain good lid hygiene with scrubbing and warm compresses. They should avoid anything that causes dryness like overly warm room, hair dryers, wind and smoking. Wrap around glasses may be helpful.
In severe cases, surgical option may be considered. This is in the form of punctual plugs, which block the tear drainage and thus increase the quantity of tears in the eyes. They may be temporary or permanent and usually is a very simple procedure done under eye drop anesthesia.
Computer Vision Syndrome
Computer vision syndrome (CVS) is a temporary condition resulting from focusing the eyes on a computer display for protracted, uninterrupted periods of time. Some symptoms of CVS include headaches, blurred vision, neck pain, redness in the eyes, fatigue, eye strain, dry eyes, irritated eyes, double vision, polyopia, and difficulty refocusing the eyes. These symptoms can be further aggravated by improper lighting conditions (i.e. glare  or bright overhead lighting) or air moving past the eyes (e.g. overhead vents, direct air from a fan).
Tips while working on Computers:
- Ensure the room is well lit
- Use proper chair with back and neck support
- Do not face the AC blow directly
- Monitor should be at a lower level than the eyes
- Take a break after every 30 minutes and try to look outside the window, as far as possible
- Use anti reflective coating on the screen or spectacles
- Blink more frequently to break the stare
- Warm compresses are helpful
- Use lubricating or moisturizing eye drops for more comfort