Most people know that staring at bright screens before bed can make it harder to fall asleep.
A new study now suggests that very bright evening light may also affect something else many people never consider—the long-term health of their eyes.
Researchers recently examined whether exposure to artificial light at night is linked with common eye diseases that become more common with age. Their findings, published in GeroScience, suggest that people regularly exposed to very bright light between 8:00 p.m. and 11:30 p.m. may face a greater chance of developing vision problems years later.
Our eyes do much more than help us see. They also help control the body’s biological clock by detecting changes in daylight. This internal clock influences sleep, hormone release, body temperature, and many other daily functions. When bright artificial light replaces darkness late at night, these natural signals can become confused.
The researchers focused on three common eye diseases. Age-related macular degeneration damages the center of the retina and makes reading and recognizing faces difficult.
Cataracts cause the eye’s natural lens to become cloudy, leading to blurred vision. Glaucoma slowly damages the optic nerve and can eventually cause permanent blindness if left untreated.
The study included more than 82,000 adults from the UK Biobank. Everyone wore a wrist monitor that continuously recorded light exposure throughout the day and night. The researchers then tracked participants for nearly eight years to see who later developed eye disease.
People exposed to more than 1,000 lux of light during the evening had noticeably higher risks of developing major eye diseases. Compared with people exposed to lower light levels, their risk of age-related macular degeneration was 31% higher, cataracts were 18% more common, and glaucoma risk increased by 47%.
The scientists emphasized that ordinary home lighting usually stays well below these levels. The higher exposures may come from powerful LED displays, very bright electronic screens, commercial lighting, or certain occupations that require intense illumination.
Although the exact reason is still being studied, researchers believe bright nighttime light may interrupt normal circadian rhythms and increase oxidative stress inside eye tissues. Blue light from modern LED sources may also contribute to damage in sensitive retinal cells over many years.
The study has several strengths, including its large size, objective light measurements, and long follow-up period. However, it also has limitations. Because it was not a clinical trial, it cannot prove that bright light directly caused the eye diseases. Other lifestyle factors may also have influenced the results.
Looking at the findings overall, the study provides another reason to think about healthy evening lighting habits.
Using dimmer lights, reducing screen brightness, limiting unnecessary screen time before bed, and creating a darker sleeping environment may help support both healthy sleep and healthy eyes. While more research is needed, these simple lifestyle changes are inexpensive, easy to adopt, and could provide benefits far beyond better sleep.
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.
For more information about eye disease, please see recent studies about how to protect your eyes from glaucoma, and results showing this eye surgery may reduce dementia risk.
Source: GeroScience study.
