Australian research has shown that a 60-minute reading task on a smartphone results in increased eyestrain symptoms and that people are more likely to hold the smartphone closer to their eyes at the end of the hour.
People who took part in the hour-long reading task reported tired, uncomfortable eyes and blur as the most significant symptoms to occur after reading on a phone for 60 minutes.
The problem is that participants naturally started to hold the phone closer to their eyes in response to visual stress, which is a self-defeating strategy. This is because the shorter viewing distance further increases the strain.
“We observed our subjects holding the smartphone at very close working distances,” said Dr. Jennifer Long, one of the vision researchers who conducted the study from the University of New South Wales.
“This is not uncommon: you can see this if you watch people in workplaces and in the street. We showed that reading from the smartphone at a close viewing distance correlates with an increase in visual symptoms,” she said.
“At this stage, our research has not established what the time limit should be for reading on smartphones. There is other research already published for desktop computers, showing a link between visual symptoms and 30 minutes of computer use, but we don’t know if this also applies to smartphones.”
To minimise eye strain when using digital devices, we recommend taking regular breaks using the 20/20/20 rule: every 20 minutes, shift your eyes to look at an object at least 20 feet (six metres) away, for at least 20 seconds.