Viewing digital screens like laptops or smartphones involves an active vision process called accommodation. It is when the eyes adjust focus from distant to near objects by contracting the ciliary muscles, shaping the lens for clear vision on the retina.
However, prolonged focus on nearby objects, like reading from a smartphone or playing games on laptops or tablets, can strain the ciliary muscles. This strain, known as "Accommodation Spasm," makes distant objects appear blurry, causing temporary pseudo-myopia or false short-sightedness. Fortunately, this condition goes away when you stop using digital screens.
When using gadgets and looking at screens, the eyes focus on nearby objects, leading to a reduced blink rate from 15 blinks per minute to about 5 blinks per minute.
Children who use gadgets may sit on adult-sized furniture, like a lower chair while using a laptop. This causes them to look upward at the screen, resulting in wider eyelid opening and increased tear evaporation. The combination of reduced blinking and wider eyelid opening can lead to dry spots on the cornea, known as superficial Punctate Epithelial Erosions (PEE). Symptoms of PEE include dry eye sensation, redness, foreign body sensation, sensitivity to light (photophobia), and burning sensation. Proper diagnosis, treatment, and prognosis of PEE require the expertise of an eye care professional. Treatment options may include artificial tears or topical antibiotic eye drops.
PEE lesions on cornea surface seen under fluorescent light
Increased cases of myopia (short-sightedness)
Spending too much time indoors with a gadget will dissuade children from doing any outdoor physical activities. Studies have found that myopic children have lower levels of dopamine compared to children without any vision problem.
Dopamine is a chemical produced in the brain and acts as a neurotransmitter, also famously known as a feel-good hormone as it creates feeling of happiness and satisfaction. It is found that dopamine helps inhibit the elongation of the eyeball, which is the leading cause of myopia.
Low levels of dopamine relate to reduced motivation and decreased enthusiasm for things that would excite most people. Getting enough sunlight, doing adequate exercise and getting adequate amount of sleep has shown to increase the level of dopamine naturally.
Eye nerve damage
Gadgets employ digital screens which produce blue light rays which in the visible light spectrum has the shortest wavelength but the highest energy. Although our cornea and lens are very effective at blocking UV rays from reaching the sensitive retina at the back of the eyeball, virtually all visible blue light passes through the cornea and lens and reaches the retina. Laboratory studies have shown that too much exposure to blue light can damage light-sensitive cells in the retina. This causes changes that resemble those of macular degeneration, which can lead to permanent vision loss.
The ways to protect your children’s eye health
My kids won’t stop using gadgets. So, what can we do to minimize potential damages to our children’s eyes?
Many kids spend a substantial period of time looking at smartphones and gadgets, which can lead to eye fatigue and neck strain. To prevent such occurrence, practice a 20-20-20 rule. Every 20 minutes, take 20-second break and focus your eyes on something at least 20 feet away. Frequent breaks while using digital devices can also prevent the occurrence of accommodation spasm or pseudo-myopia. Remind your children to blink frequently and fully while using their devices and use moisturising eye drop when their eyes feels dry.
Limit time exposure to digital screens
The American Academy of Paediatrics have provided a recommendation and guideline for media usage in children from birth to adulthood. Among its recommendations are:
For children younger than 18 months old, avoid the use of digital screen other than video chatting.
For children aged 2 to 5 years, limit digital screen use to 1 hour/day of high quality program.
For children aged 6 and older, there should be consistent limit on the time spent using media, and the limit set must ensure adequate time is allocated for sleeping and physical exercise.
Encourage outdoor activities
It is a well-known fact that outdoor activities such as running, swimming, doing sports and camping keep us healthy, tightens bonds between family and most importantly distracts children from using their gadget. However, our busy schedule and our hot tropical climate will make daily exercise difficult. If this sounds familiar, allocate a period during weekends to exercise, or arrange activities that can be done together in a group, such as camping, participating in running events or hiking. Also, exposure to the morning sun encourage our body to produce more serotonin, a hormone that controls sleep/awake cycle and increases the level of dopamine produces by the body.
Correct Usage of Digital Device
If a digital device is an essential part to your children for any reason, ensure that they practice correct posture while using their devices. The height of the chair should be adjusted so that the laptop/tablet screen is at 15 degrees below their eye level. Looking up to the devices while lying down or sitting in a smaller chair will cause their eyelids to open wider which can lead to dry eyes. The digital screen should be at least 30-40cm away from their eyes. The device should be used under proper lighting, preferably natural light from the sun. If the screen glare is too strong, consider getting a blue light screen or filter that can reduce the level of blue light that can get into their eyes.
Annual Eye Examination
The American Optometric Association (AOA) has released a guideline for paediatric eye health. Research has provided evidence that supports the need of children ages 6 to 18 years to receive a comprehensive eye exam before entering school and annually thereafter. The recommended comprehensive eye exam has shifted from a two-year to a one-year frequency due to increased prevalence of eye and vision disorders.
And finally, look out for sign of eye problem in your child such as headaches, dry eyes, neck and shoulder pains, frequently rubbing their eyes, squinting while reading or watching television, or looking at object with chin raised or head tilted. Factors that could contribute to this are poor lighting, bad seating posture, excessive glare from the screen or simply fatigue.