‘Dry eye’ is a disorder where there is inadequate production, early evaporation or poor quality of the tear film covering the surface of the eye. This leads to a wide variety of symptoms which include watering, irritation, redness, grittiness and blurred vision.
With the turn of century, a number of lifestyle modifications have reduced the threshold of ocular discomfort in patients. Also, With the new advent of ‘digitalisation’, an average Indian spends approximately 8 hours a week on mobile phones, televisions, etc.
WHAT IS COMPUTER VISION SYNDROME?
People who spend considerable time on video terminal displays like televisions, mobile phones often complain of some ocular discomfort which may or may not be associated with
· Redness
· Grittiness
· Foreign body sensation
· Irritation
· Transient loss of vision, etc.
HOW TO FIND OUT IF I HAVE DRY EYE?
A large number of studies conducted across the world have reported that almost every 4th person has some symptoms of dry eye. So if you notice dryness of eyes or excessive watering, grittiness and redness etc, it is possible that you might be suffering from the condition.
Because of the wide variety of causes and symptoms associated with dry eyes, it is often under diagnosed and under investigated. Patients usually resort to over the counter tear substitutes. Though these provide symptomatic relief, the symptoms recur as soon as the treatment is terminated.
For these reasons, it’s important to investigate and diagnose the causative factor leading to such symptoms to refine our current management of dry eye.
WHY DOES DRY EYE OCCUR?
Dry eye is because of a defect in the tear film. Broadly it is either because of reduced tear secretion, excessive or early evaporation of the tear film or poor quality of tear film. Most cases of dry eye are attributed to the excessive screen time responsible for the reduced blink rate.
HOW DOES BLINKING AFFECT DRY EYE?
Our eyelids have glands called meibomian glands near our lashes that secrete an oily liquid which protect the aqueous content of the tear film. The mechanism of blinking brings about the expression of these oils from the glands, which then forms a protective layer over the aqueous layer and prevents its evaporation.
When we focus for some time, like we do while watching tv or operating a mobile phone and laptops, we tend to blink less frequently. This leads to loss of protective oily layer and evaporation of the tear film.
Other causes of defective tear film include metabolic tendencies, systemic and topical medication induced toxicity among others.
Not all symptoms of dry eye can be managed by tear substitutes alone. It becomes essential to investigate, unmask and pounce on the prime mover of dry eye.