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In her six-part undercover agent Ruby Redfort series, Lauren Child says, “Blink and You Die.” Your ophthalmologist, however, will tell you, “blink, or you’ll get dry eyes.”
You see, humans are hard-wired to blink. It is one of our involuntary reflexes, and usually, we blink between 12 and 15 times per minute, although you can blink an average of 22 times per minute in relaxed conditions.
Unfortunately, the increasing amount of time we spend in front of computers and digital screens has compromised our blink reflexes — thus, the pressing need to find solutions for dry eyes, among other consequences of long-term electronic device use.
Blinking and Dry Eyes
We blink involuntarily because we must. It is a reflex that protects the surface of our eyes (i.e., the ocular surface, particularly the anterior or front-facing layer of the cornea and conjunctiva).
Specifically, blinking starts a series of lightning-quick processes:
- Triggers the secretion of tears
- Spreads the tears over the eye surface
- Drains excess moisture
In short, blinking activates, replenishes and maintains the integrity of the tear film that keeps the eye surface moist, clear and smooth.
Therefore, whenever you don’t blink enough or don’t blink correctly, you undermine the very process that keeps your tear film healthy and your eye surface adequately lubricated. Consequently, blinking abnormalities can lead to dry eye syndrome or dry eye disease.
Computer Use and Blinking
How does staring at a computer and other digital screens (e.g., e-book readers, tablets, mobile phones) compromise your blinking reflex?
1. Fewer Blinks per Minute
Staring at a computer monitor, particularly focusing on reading and viewing what is on it, reduces our blink rate. A study found that reading, whether from a book or a tablet, significantly decreased the subjects’ blink rates.
Therefore, computer use leads to lower blink rates. In other words, you blink fewer times per minute when you use a computer.
Note: The study did show there was no significant difference between blink rates when reading from a book and a computer. Both activities lead to lower blink rates.
2. More Incomplete Blinks
Aside from the blink rate, one other factor is crucial to the health of the eye surface. This is the blink amplitude.
When you talk of amplitude, sound waves often come to mind. A sound wave amplitude is the height of a sound wave or the difference between its crest (the highest part) and its trough (the lowest part).
Now blink amplitude is something similar. It is the difference between the eyelid position at blink start (the eyelid’s highest position) and at full close (the eyelid’s lowest position). A high blink amplitude indicates a big difference between the position of the eyelid at blink start and during the actual blink.
In other words, the more fully you close your eyes when you blink, the higher your blink amplitude is.
Why is blink amplitude crucial?
Closing your eyes completely when you blink serves to thicken your tear film’s top oily layer, which protects the underlying water layer from excessive evaporation. Thus, when you don’t close your eyes totally when you blink (i.e., when you blink incompletely), more water evaporates from the tear film, and the drier your eyes become.
Unfortunately, incomplete blinks increase when we read from a computer monitor. A study found that subjects reading from a computer screen had a significantly higher percentage of incomplete blinks than those reading from a printed page.
Research by Akkaya et al. confirms that long-term computer use leads to eye dryness. The researchers found that those who use a computer for eight hours a day have a significantly lower tear break-up time (i.e., have a more unstable tear film) than those who spend less than an hour daily on a computer.
Simply put, the water layer of the tear film evaporates quicker among long-term computer users. Ergo, long-term computer use can cause eye dryness.
Computer Vision Syndrome
When we stare for hours at a computer monitor, our eyes have to read from left to right (may be right to left, depending on your language), look up and down, and constantly focus, refocus and shift focus.
All the while, the screen adds to the challenge with its continuous glare and flickering. Working on a computer, therefore, greatly strains our eye muscles.
Then, of course, we also blink fewer times and tend to blink incompletely when working on a computer. These cause eye dryness.
Therefore, long-term computer use can cause computer vision syndrome (CVS).
Computer vision syndrome is a general term encompassing various eye problems caused by frequent, persistent and long-term computer use.
One such issue, as discussed earlier, is eye dryness. Other CVS symptoms include eye redness, blurred vision, double vision, headaches, and eye irritation.
Solutions for Computer Use-Induced Dry Eyes
The most effective solution is to cut back on your screen time. In other words, use your computer, tablet or mobile phone for shorter periods.
Of course, if your work requires you to stare at a computer screen for hours, you can’t do anything about this other than take regular screen breaks.
You can, however, still limit your children’s screen time. You should also get your children’s eyes checked by an eye specialist for kids to see if they are not suffering from dry eyes and other computer vision syndrome symptoms.
You should also reduce the glare of your monitor and don’t work on your computer or stare at your tablet or mobile device screen when it’s dark. Make sure, too, to arrange your workstation so that your computer screen is around 20-28 inches away from your face and you’re slightly looking down on it.
Whatever you do, do not forget to set an appointment with your eye doctor. If left unchecked, dry eyes can lead to corneal scarring and tissue damage.
Gulf Eye Doctors is a leading eye centre in Dubai.
We use advanced techniques to treat a wide range of eye conditions, and we can help you with your dry eyes. Contact us today!