Night-time screen use linked to myopia and poor sleep

People with myopia have delayed circadian rhythms and lower production of melatonin compared to people with normal vision and are more likely to experience poorer sleep quality, a Flinders University study found.

In the study, conducted in collaboration with the Flinders University Sleep Institute, the circadian timing and production of melatonin was measured in myopic and non-myopic university students in their twenties, using saliva and urine samples.

“These findings provide important evidence that optimal sleep and circadian rhythms are not only essential for general health, but also for good vision,” said study lead optometrist Dr Ranjay Chakraborty from Flinders Caring Futures Institute.

According to the study, myopic participants also take longer to fall asleep, sleep for shorter periods and are more likely to go to bed later or be ‘night owls’ compared to those with normal sight. These sleeping habits are related to people with myopia spending more time on blue-light-emitting devices or studying before going to bed, said Dr Chakraborty, adding to the growing evidence of an association between disruption of the circadian rhythm and the development of myopia.

“Disruptions in circadian rhythms and sleep due to the advent of artificial light and the use of light-emitting electronic devices for reading and entertainment has become a recognised health concern in several fields, but its impact on eye health has not been studied extensively,” he said.