These days, many people worry about how much time they are spending looking at a computer or handheld device. It’s not uncommon to have dry eyes, headaches or blurred vision after prolonged periods of screen time. Usually taking a break can help, but is there any lasting damage being done to your eyes that you may not be immediately aware of?
Digital eye strain happens when a lot of time is spent using near vision, for example, reading on screen or playing online games. Digital eye strain does not cause permanent damage to your eyes but can be uncomfortable. One of the main symptoms is temporary blurred vision but other signs such as sore and tired eyes, dry eye and headaches are also associated with digital eye strain.
Computer Vision Syndrome
Computer vision syndrome is an umbrella term for conditions that result from looking at a computer or smartphone screen. “It’s most prevalent with computers, and typically occurs when looking at a screen at arm’s length or closer,” says Dr. Matthew Gardiner, an ophthalmologist with Harvard-affiliated Massachusetts Eye and Ear Infirmary.
Dry eyes can be caused by a lack of blinking. “When you look at a screen, you’re so involved that you forget to blink. The blink rate goes from 15 times a minute to five or seven times per minute,” explains Dr. Gardiner. But you need to blink to re-establish the tear film on the eyes — a thin layer of liquid that protects the surface of the eye. If you don’t blink enough, your eyes dry out, causing blurry vision and discomfort.
The other main problem from staring at a screen too long is eyestrain. Dr. Gardiner says one possible cause of this is the brightness or glare that comes from the electronic screen. “Bright light sources can feel uncomfortable, especially if you have cataracts,” Dr. Gardiner says. Eyestrain can also result from focusing up close on a screen without the proper eyeglass prescription. “Any time you strain to see something, maybe because you need reading glasses and have resisted getting them, you can get a headache. You can exhaust your eyes’ ability to focus,” says Dr. Gardiner.
If you have eyestrain and headaches after looking at the computer screen for long periods, make sure your eyeglass prescription is up to date. It’s also important to take a break from electronic screens every 15 to 30 minutes, just for a minute.
Can too much screen time increase the likelihood of developing short-sightedness?
Short-sightedness, or myopia, is increasing throughout the world. Family history, ethnic background, environment (living indoors, in cities) and carrying out near tasks, such as screen use, have all been linked to the development of myopia.
However, there is no clear evidence to suggest that screen time alone is the direct cause. But, there is good evidence to suggest that children who spend more time outdoors are at lower risk of developing short-sightedness.
The World Health Organization guidelines, issued in early 2019, recommend no screen time for children under 3 and screen time of no more than 1 hour for children ages 3 and 4. “Less is better,” the WHO recommendations say.
However, The Royal College of Paediatrics and Child Health, recommend that decisions on screen time be made within the family. Some screen time can help children learn, researchers noted.
What is blue light and how can it impact my eyesight?
Sunlight contains red, orange, yellow, green and blue light rays. Combined, this spectrum of coloured light rays creates what we call ‘white light’ or sunlight. Depending on where they fall on the spectrum, light rays have long wavelengths (with less energy) or short wavelengths (with more energy).
Blue light is a high-energy visible light and has shorter wavelengths. It is known as blue light because it is on the violet-blue band of the spectrum. Blue light is naturally present in sunlight but is also something we can see from screens such as TVs, computers, smartphones and tablets.
There is currently no scientific evidence that blue light causes damage to the eyes. However, there is evidence to suggest that carrying out near tasks, involving looking at something close-up, such as using mobile devices, screen time and reading a book, can increase eye strain for those who do this for long periods of time.
Using screens close to bedtime may also contribute to poorer sleep. This may be because blue light is linked to the suppression of the hormone melatonin which makes us feel sleepy. However, there is a range of other factors linked to disrupted sleep.
Can blue light filtered lenses help?
Some people report that lens coatings that filter blue light make their eyes feel more comfortable or are helpful before bed, but there is no clear scientific evidence to support this. There is also no evidence that these kinds of coatings prevent eye disease.
Tips for to help protect you and your families eyes from computer eyestrain.
Here are 10 tips to help protect your child’s eyes from computer eyestrain:
- Set a kitchen timer or a smart device timer to remind you or your children to take a break.
- Alternate reading an e-book with a real book and encourage children to look up and out of the window every two chapters.
- After completing a level in a computer game, look out the window for 20 seconds.
- Avoid using a computer outside or in brightly lit areas, as the glare on the screen can create strain.
- Adjust the brightness and contrast of your computer screen so that it feels comfortable to you.
- Use good posture when using a computer and when reading.
- Hold digital media farther away, 18 to 24 inches is ideal.
- Create a distraction that causes your child to look up every now and then.
- Remember to blink when watching a screen.
- Try not to watch TV for longer than 2 hours at a time.
If you have any questions or concerns about your eyes, please do not hesitate to get in touch.