The effect of VDU (visual display unit) work on kids vision

Some scary stats...

  • The average child now has access to five computer devices
  • On average, a 3-4 year old will spend 3 hours a day in front of a screen
  • Children aged 5-7 years old spend 4 hours looking at screens
  • 8-11 year olds spend 4.5-8 hours
  • Teenagers use devices for 6.5-11 hours

This amount of screen work can lead to increased vision problems and eye strain.

Common symptoms of vision problems to look out for include:

  • Blinking
  • Eye rubbing
  • Squinting
  • Holding books really close
  • Unwillingness to read or do detailed tasks
  • Headaches

The cons and pros

The new LED screens we all use emit more blue light. Blue light is very close to the UV spectrum, a form of light that is damaging to the eye. Blue light can penetrate a child’s eyes more efficiently than an adult’s, making kids more prone to damage from blue light. Blue light may also disrupt the normal REM sleep patterns and make it harder for kids to sleep at night.

Our blink rate is markedly reduced when focusing on a screen – it decreases to just 30% of the normal rate. This leads to dryness and eye irritation.

With long periods of near focus, children’s eye muscles tense up. This may lead to a change in the shape of the eye, resulting in short-sightedness. Studies have shown there is a strong correlation between prolonged screen usage and increased risk of short-sightedness.

Screen work isn’t all bad, though. It can improve a child’s learning experience and make it more fun. There are even important applications for vision, such as in the treatment of lazy eyes. We just have to take a few preventative steps and early treatment to give kids the best vision possible.

Limiting screen time

The best way to prevent these changes and problems is to limit screen time – including time using mobile phones. Ideally, children younger than 2 years old should have no screen time. Pre-schoolers should have only 1 hour, whilst 2 hours a day is a good limit for school-age children.

Regular breaks are another great way to prevent problems. The simplest method is the 20-20 rule: After 20 minutes of screen work, have your child look into the distance or close their eyes for 20 seconds. This lets the eyes relax after a period of working hard to focus on a screen.

Another fantastic way to get kids away from screen work is to encourage outdoor activity and sports.

Annual eye checks are important

It’s important for kids to have their eyes tested annually so any changes can be picked up and treated early. In addition to correcting vision, glasses lenses now have blue light blocking and UV filters that help prevent the harmful light from entering the eyes.

Ming Wang, optometrist