In the digital age, the number of screens that are available to any individual has increased exponentially. The amount of information provided through said screens via the internet has also increased, resulting in prolonged screen time.
The pandemic has further exacerbated the problem of excessive screen time, as work, meetings and classrooms have all shifted online. This increase in daily screen time is not without effect — it can irritate the eyes, cause eye pain or even induce headaches.
Such symptoms are a result of Computer Vision Syndrome, which is defined by the American Optometric Association as a group of vision-related issues that come from long-term use of electronic devices. The average adult spends 11 hours a day looking at a screen, and 50 to 90 percent of computer users report symptoms of Computer Vision Syndrome.
According to Dr. Christopher Starr, an ophthalmology specialist at Weill Cornell Medicine, there are two main factors that contribute to Computer Vision Syndrome: near vision and blink rate.
Near vision occurs because screens often lie within a foot away from the face, forcing muscles in the eyes to maintain focus at a close distance. After a long enough period of time, the muscles start straining to keep objects in focus and grow tired, causing symptoms such as headaches and eye pain.
The second factor involved in Computer Vision Syndrome is blink rate, or the number of times that one blinks their eyes every minute.
“When you’re on the computer, [your] blink rate is known to decrease — up to about 50 percent less blinking,” Starr said.
Usually, blinking allows for the distribution of tears across the eyes’ surface, keeping them well-lubricated. Consequently, a decrease in blink rate hinders such distribution and can cause dry spots on the eyes. Dry eyes can then result in symptoms such as eye redness, burning, stinging or blurriness of vision.
Starr suggested one way to reduce symptoms is to reduce eye strain through the 20-20-20 rule: After 20 minutes of screen time, people should look at something 20 feet away for 20 seconds and repeat as necessary.
But Starr said the 20-20-20 rule does not fully address the dry eyes and reduced blinking factors. Instead, he proposed an amendment to the rule, making it the 20-20-20-20 rule. Starr’s rule adds a fourth 20, which represents 20 seconds of closing the eyes. Closing the eyes allows glands in the eyelids to produce an “…oil slick [that] helps to stabilize the tears and prevent evaporation,” Starr said.
In addition to the 20-20-20-20 rule, eye strain can be decreased by sitting with proper posture in front of computer screens. The NVision eye surgery center also recommends maintaining a level of light in the room that is around the same brightness level as the screen.
Aside from Computer Vision Syndrome, excessive screen time can also indirectly affect one’s health through blue light, a type of visible light emitted by the display screens of digital devices. Blue light is stimulating, so looking at a bright screen emitting blue light will excite the brain and can make it more difficult for people to fall asleep.
To combat sleeping difficulties, the American Academy of Ophthalmology recommends switching electronic devices to night mode or dark mode during evening hours. Night mode reduces both screen brightness as well as blue light emission.
However detrimental excessive screen time may be, the symptoms such as tiredness or decreased productivity are only temporary.
“It doesn’t usually lead to permanent eye damage or blindness,” Starr said. “[But] it can certainly reduce quality of life and work productivity.”