Computer Vision Syndrome: How Screen Time Impacts Children’s Vision
When the visual demands of a task exceed an individual’s visual abilities to comfortably perform them, symptoms of computer vision syndrome (CVS) may emerge. Children who spend two or more continuous hours every day at a computer or using a digital device are at the greatest risk for developing CVS.
Common Symptoms of Computer Vision Syndrome
- Blurred vision (mostly distance)
- Dry eyes
- Neck and shoulder pain
- Reduced quality and duration of sleep
Common Causes of CVS
- Poor lighting
- Glare on a digital screen
- Improper viewing distances and angles
- Poor seating posture
- Uncorrected vision problems
- Prolonged periods of screen time
Uncorrected Visual Problems May Contribute to CVS
The extent to which individuals experience the symptoms of computer vision syndrome often depends on uncorrected visual findings along with the amount of time spent looking at a digital screen.
Children, more often than adults, have uncorrected vision problems and inadequate eye coordination abilities. That is because children may not recognize that their visual blur is abnormal. Therefore, they usually do not complain of or recognize any visual problem.
In fact, most parents are not aware of any visual problems for their children. Typically, visual deficiencies are first detected by a vision screening performed by their pediatrician or at school.
Digital Screens Place Added Demands on the Eyes
Viewing a computer or digital device is very different from reading a printed page from a book or letter. That is because they emit pixelated light. As a result, the letters on these devices are not as sharply defined. Digital screens also reduce the level of contrast for the letters vs. the background and produce glare and reflections.
All of this makes viewing a screen more visually demanding and requires greater near focus along with increased eye movement in order to maintain a single clear image. This strain on the eyes often results in blurred distance vision (nearsighted) rather than near blur, even after cessation of use.
Computer Vision Syndrome Parallels Increase in Myopia
Over the past 30 years, there has been a large increase in computer use, both for school and at-home purposes. This change in behavior parallels an increase in myopia among children.
The National Eye Institute has conducted several studies, finding an overall trend of increased nearsightedness among Americans.
Myopia is related to eye length, and studies show that eye growth is slowed by dopamine production. Dopamine production increases by spending more time outdoors. Eye growth occurs very quickly during infancy, slows down during pre-puberty, and then reaches adult size during teenage years. Therefore, school-age children are at critical ages for proper eye growth and development.
Research suggests that spending an average of three hours outdoors daily, would potentially mitigate myopia development and/or progression.
Too Much Screen Time Impacts Posture
Posture can also be impacted by computer use.
Some children tilt their heads at odd angles because either they need glasses, or their current prescription isn’t proper or updated. Additionally, children tend to bend toward the screen and hunch their shoulders in order to be near their computer, tablet or cell phone screen.
The duration of these postures can have a large impact and result in muscle spasms or pain in the neck, shoulders or back.
In fact, children under 8 spend an average of 2 hours per day on their digital display. This number increases as children get older reaching 9-10 hours per day in teenage kids.
Disrupted Sleep Patterns Could Suggest Vision Problems
If your child has trouble sleeping, screens have been shown to intrude on sleep duration and cause delays in falling asleep.
Digital screens emit blue wavelength light that suppresses sleep hormones and interferes with the body’s circadian rhythm. The body and mind can become confused with exposure to light emissions at night, causing increased alertness and suppression of the sleep hormone melatonin. Alertness is also impacted if the screen content is exciting, dramatic or scary, making it harder to both fall and stay asleep.
Furthermore, during the day, screen time should not replace outdoor activities. Not only does time outdoors potentially help regulate eye growth, but it is beneficial for sleep regulation, helping to ensure that kids are tired at bedtime.
Testing for Computer Vision Syndrome
If you are concerned about computer vision syndrome, a visual screening with a pediatrician is an important first step. However, every school-aged child should have an eye doctor visit. The child may pass the screening but still have a slight prescription impacting them.
At the appointment, an eye doctor will determine the appropriate lens power needed to compensate for any refractive errors (nearsightedness, farsightedness or astigmatism) and examine how the eyes focus and move together. The best vision is obtained when the eyes work in unison to obtain a single clear image.
Eyeglass Lenses Provide Protection
If computer vision syndrome is detected, eyeglass lenses can be prescribed to meet the visual demands of computer viewing. There are special lens designs and powers, along with coatings and tints to help maximize visual acuity and comfort.
Some children may not need a prescription but would still benefit from blue light filters that can be added as a lens coating. Blue light has the potential to impact melatonin levels and reduce sleep but can additionally cause oxidative stress on the retina of the eye.
Over time, this stress on the retina might increase an individual’s risk for age-related macular degeneration as they age. Children will eventually become elderly, and they will have been exposed to far more blue light, from digital devices, than any previous generations.
Screen Time Tips for Your Child
- Screen location. Should be positioned 15 to 20 degrees below eye level (4 to 5 inches) and 20-28 inches from an individual’s eyes.
- Duration of use. Should be minimized as much as possible, try to stay under 2-3 hours daily. Cessation of screen use 2-3 hours before bedtime.
- Rest breaks. To prevent eyestrain, incorporate the 20/20/20 rule. For every 20 minutes of computer viewing, look into the distance of 20 feet for 20 seconds to allow the eyes a chance to refocus.
- Blinking can be reduced while viewing a screen. The best habit is to close the eyes and squeeze gently. This helps to release oils and keep the surface moist. Repeat this motion every time you do some repetitive action like clicking the mouse as a reminder to blink. This habit will help minimize the chance of developing dry eyes.
Annual Eye Exams are Essential to CVS Prevention
As the demand for computer-based learning grows, an annual eye exam has become essential to children’s health and wellness. Your local optometrist can identify and monitor the symptoms of computer vision syndrome and other eye problems. Contact Family Health Centers today to request an appointment at one of our conveniently located health centers in your community.