Changing the clocks for daylight saving time may do more than make people feel tired.
A new study suggests that the one-hour time change could also affect the health of the eyes by changing the risk of certain diseases that damage the retina. The findings were published in Scientific Reports.
The research was led by scientists at Northwestern Medicine, who wanted to understand whether changes in sleep and the body’s internal clock could influence blood vessels in the eye.
Previous studies have already linked daylight saving time, especially the spring clock change, with a higher risk of heart attacks and strokes.
The retina is the light-sensitive tissue at the back of the eye that allows us to see. It also plays an important role in the body’s circadian rhythm, the internal clock that helps control sleep, hormone release and many other daily body functions.
To investigate the possible link, the researchers examined health insurance records from more than 18 million adults aged 18 to 64.
They looked for new cases of several retinal blood vessel diseases after the spring and fall daylight saving time changes and compared them with similar periods in summer and winter.
The results showed a clear difference between the two clock changes. During the month after the spring transition, when people lose one hour of sleep, the risk of developing some retinal diseases increased by as much as 30 percent. These included proliferative diabetic retinopathy and neovascular age-related macular degeneration.
In contrast, during the month after the fall time change, when people gain one extra hour of sleep, the risk of retinal vein occlusion and proliferative diabetic retinopathy was about 20 percent lower than during the comparison period.
The researchers believe sleep loss and disruption of the body’s internal clock may trigger inflammation and changes in metabolism that could affect the tiny blood vessels inside the retina. Because the retina has one of the body’s richest networks of small blood vessels, it may be especially sensitive to these changes.
The study does not prove that daylight saving time directly causes eye disease. It only found an association, and other factors may also play a role. The researchers also noted that the study included only three years of data and should be confirmed in larger databases.
Even so, the findings suggest doctors may want to pay closer attention to people who develop new vision symptoms after the spring clock change. Future studies will examine whether improving sleep or reducing circadian disruption could help protect eye health.
Review and analysis: This large nationwide study provides valuable evidence because it included millions of patients, giving the results strong statistical power.
However, it was an observational study based on insurance records, so it cannot prove cause and effect. More research is needed, but the findings strengthen growing evidence that even small disruptions to sleep and body clocks may influence overall health, including the eyes.
If you care about eye health, please read studies about how vitamin B may help fight vision loss, and MIND diet may reduce risk of vision loss disease.
