Is All That Screen Time Hurting Your Eyes?

With the various lockdown measures across the world (and the circuit breaker measures in Singapore), most of us, regardless of age, are spending a lot more time on digital devices. Be it staring at our laptops for longer hours as we work from home, or watching YouTube and Netflix videos to stave off weekend boredom, device usage has hit the roof during this Covid-19 period. Needless to say, digitally-native teenagers and children inevitably spend more hours on digital devices too, especially with the implementation of home-based learnings.

The overuse of digital devices such as the television, computer, tablet, or smartphone, can lead to an eye condition commonly termed “digital eye strain”, which can be frustrating as the symptoms can be very persistent. It can affect your quality of life, not only reducing your productivity at work but also your ability to fully enjoy leisure activities.

1. It causes Dry Eye Syndrome.
   Dry eye syndrome is a disorder of tear production and quality, reduced eyelid blink, and the impact of these 2 factors on the health of the eye surface (i.e. the cornea). When the eyes are kept open for prolonged periods without blinking, or if tear production is inadequate, the eye surface tends to dry out and this produces some of the visual symptoms and sensations we experience.

   A healthy and stable tear film is often underestimated as a contributor to vision and comfort. A tear film is a refracting surface, just like the cornea. In fact, a disturbed tear film can alter the measured spectacle prescription, and can also contribute to aberrations like glare and halos.

2. It leads to an overuse of the eye muscles controlling near focusing.
   Focusing up close for near vision requires a delicate interplay of changes occurring in the eyes. The ciliary muscles of the eye control the ability of the crystalline lens to bring images into focus onto the retina.

   With prolonged screen time imposing a need to constantly focus on near objects, the ciliary muscles need to stay in a state of continuous contraction, leading to a sensation of eye fatigue.

3. It increases your need to maintain continued precise and coordinated eye movements.
   Reading text or images requires a precise coordination between the brain and the muscles controlling eye movement, in order to keep the words or images in the precise position on your retina. Both eyes need to work in coordination with each other, and your eyes have to perform very precise acceleration and deceleration movements as you scan down the page. On top of that, focusing for near requires you to keep your eyeballs in a very slight inward-turning position to align the line of sight of both eyes.

In general, digital eye strain, whilst causing you to experience much discomfort, has no major long-lasting impact on your vision or overall eye health, because it gets better with a reduction in screen time and simple measures to rest the eyes.

However, if there is an underlying issue with tear production or quality, or if there are erosions of the ocular surface as a result of dry eye, treatment will be required. With treatment, the vast majority of people experience a significant improvement in their symptoms and functioning will not have any lasting damage to their eyes or vision.

If your eye symptoms are related to the overuse of digital devices, and if there hasn’t been any significant or abrupt visual change or pain, it is entirely reasonable to first start on some simple measures to reduce eye fatigue.

However, if these symptoms persist, it is usually an indicator that either firstly, your condition is significant enough that it warrants a medical assessment by an eye specialist (for example, if there are abnormalities in the tear film, or if there are corneal surface erosions), and that you may need treatment, or secondly, that one needs to ensure that there are no other more sinister eye conditions that may be at play.