To understand dry eyes, let us first understand the importance of tears for our eyes. Tear is not just water but is much more complex than that. It forms a gel like layer of the over the eyes to protect it.

The importance of tears can be easily judged by keeping the eyes open continuously for a few minutes (which allows the tear film to evaporate) and feeling the resulting severe burning and irritation.

Some of the more important functions of the tear film are:

Tears protect the eye – It keeps your eyes wet, lubricated and comfortable. The surface of the eyes expects a wet environment. Without this protective film the eye can develop erosions and even ulcers and scarring. Normal tears contain many anti-infective agents which help fight infections.

Tears have various proteins and nutrients and nourish the eye. Without it the surface of the eye becomes unhealthy and more prone to stress.

Tears provide a good clean wet surface and thus help in forming a clean sharp image in the eye. So, if you don’t have a good stable tear film, the vision may not be nice and sharp.

That's the most common impression and that's what most people assume when they buy glasses with anti-glare coat or blue cut etc. Unfortunately this is a myth and the light coming from the screen has nothing to do with the resultant dryness in eyes.

"Computer vision syndrome" or dryness secondary to computer use is secondary to reduced blinking. When a computer user is looking at screen, his / her blinking becomes infrequent. A normal person blinks 12 - 20 times a minute. However during computer usage, the blinking goes down to 2-3 times a day. This is the main cause of dryness and the resultant symptoms of computer vision syndrome.

Dry eyes can be a debilitating problem for a lot of patients. Some of the symptoms include:

• Feeling of grittiness or foreign body inside the eye
• Aching or sore eyes
• Eyelids feel “heavy” or tired
• Burning sensation
• Eyes which tire easily even while reading or watching TV
• Intolerance to Contact lens.
• Excessive mucus discharge
• Watery eyes
• Eyes easily irritated by smoke, water, soap or other irritants
• Increased sensitivity to light
• Fluctuating vision
• Blurred vision

Watery eye seem to be contradictory to the term “dry eyes” but is also a common problem. Painful, irritated eyes stimulate production of very watery tears as a reflex. These “reflex tears” is a less balanced type of tear which is produced to flush out foreign bodies and protect the eye from irritants. But this is unable to form a good protective tear film.

Mild to moderate dry eye is usually a ‘quality of life’ issue.  But moderate to severe dry eye can affect vision and can severely impair the quality of life due to chronic pain, eye sensitivity, light sensitivity and restricted activities. Very severe dry eye may lead to desiccation of the eye surface with ulceration and perforation of the cornea, infections, and potential blindness.

The answer to that question is a big YES. There is a lot of variability of symptoms between patients even with the same duration of computer use. This typically happens due to intrinsic susceptibility of each person as well as some external factors. Its important to find out about these factors as it can help improve symptoms.

Apart from the duration of screen time, other factors that may be involved include

• Other diseases such as arthritis, allergies etc.
• Use of some drugs such as isotretinoin for acne, antiallergics, antidepressants, BP medications, Contraceptive pills etc.
• Nature of computer work such as graphic designing, proof reading, prolonged use of excel sheets etc.

Now that we've understood the background of Computer Vision Syndrome, we can come to the crux of the issue which is " How to tackle it?"

Since the main issue is excessive screen time, ideally we should start with reducing it. Easier said than done in this era. Inspite of being a doctor and not dependent on prolonged computer use for my livelihood, I've spent numerous hours staring at a computer screen to write the articles on this website.  What about people in IT industry or for that matter people who're working from home due to pandemic.  Most people are now dependant on gadgets to carry on with their profession. However what can still be done is break the continuity of work.

20-20-20 rule

After every 20 minutes take a break, focus beyond 20 feet for at least 20 seconds. To this I would also add "closing the eye" for another 20 seconds. These steps not just reduce dryness, but also reduce fatigue and spasm of eye muscles.

Treatment starts with an assessment of severity, type of dry eyes and finding other contributing factors. Though there are various tests, none of them are good enough in isolation. A subjective assessment by your eye doctor is most important and may be combined with some of these tests to get a complete picture.

The aim of dry eye treatment revolves around 3 aspects

• Increasing production of natural tears
• Preventing loss of tears from the eye due to evaporation and drainage
• Providing artificial tear substitutes

Increasing the production of natural tears though a logical course of action is usually difficult. However stopping or reducing medications which reduce tear production - if possible - can be a good way to start “dry eye” treatment.

Another important part of dry eye treatment is preventing loss of tears from the eye. That's where the previously stated 20-20-20 rule comes in. However increased evaporation of tears also commonly occur due to what is called "Meibomian Gland Dysfunction" or MGD. These glands secrete an oil which becomes part of the tear film and helps it retain it in the eye. The dysfunction of these glands allows the tears to evaporate away leaving behind a dry surface. This dysfunction of meibomian glands is treated by a regime of

• Lid hygiene which involves scrubbing the margins with diluted baby shampoo or special lid wipes. This process cleans and opens the pores of the oil glands and reduces bacterial load.
• Hot fomentation which involves applying heat to the lids. This process melts the thick oily secretions allowing them to flow out
• Lid massage which involves massaging the lids so as to squeeze out these melted oily secretions.

You need to discuss it with your eye doctor to understand the role of MGD in your case and the extent of treatment required.

Another important factor is use of air conditioners and heaters. Air coming from these gadgets is dehydrated and direct exposure to it on the face can also contribute to dryness. Improving the humidity of environment by turning down the AC and redirecting the vents away from the face can also help.

Computer Ergonomics can also help in reducing not just the strain on eyes but also the rest of the body. Placing the reading material in such a way so that the eyes are directed downwards while reading allows reduced exposure of the eyes and reduced evaporation of tears. An that is why it is recommended to keep the top level of computer screen at the same level with eyes

Artificial tear substitutes have been and are still the mainstay of dry eye treatment. These are usually gel forming polymers which tend to stick to the eye surface keeping it wet. Though there are numerous kinds of artificial tear substitutes in the market the main differentiating features are

Concentration of the polymers– With lower concentration, eye drops are more liquid which easily spreads onto the eye surface. On the downside these stay in the eye for a much shorter time and needs to be repeated at more frequent intervals. With higher concentrations these polymers form thicker gels which stay in the eye for a longer time. On the downside these are stickier and cause transient blurring of vision for a few minutes.

Preservative used – Most eye drops contain preservatives which have their own toxic side effects on the eye. Since dry eye is a chronic problem requiring use of eye drops for many months to years, it becomes important to avoid these preservatives. Newer preservatives have been introduced which are much less toxic and safer for long term use. Some preparations which are totally preservative free are also available though they are more expensive.

Presence of additional wetting agents – Some artificial tear preparations have an added wetting agent which is absorbed by the surface of the eye keeping it wet and hydrated long after the artificial tear has left the eye.