Researchers analyzed data from over 400,000 participants in the UK Biobank, who were between 40 and 69 years old when they participated from 2006 to 2010, and provided details of their sleep behaviors.

The study defined normal sleep duration as anywhere from seven to less than nine hours per day.

Anything outside of this range was considered as under or oversleeping. Researchers also categorized participants by chronotype, whether they were morning people or “night owls,” and if they snored.

Findings show that during the average monitoring period (about 10.5 years), there were 8,690 cases of glaucoma diagnosed among study participants.

The findings also indicate that participants who developed glaucoma tended to be older, male, have smoked, and have high blood pressure or diabetes compared to those who didn’t.

“This is an excellent observational study that opens up opportunities for future studies to try to better understand the mechanisms behind its findings,” said Wachler.

According to the Centers for Disease Control and Prevention (CDC)Trusted Source, about three million Americans have glaucoma, the second leading cause of blindness worldwide.

Researchers grouped participants by the degree of insomnia severity, such as trouble falling asleep at night or frequently waking, which was classified as never, sometimes, or usually.

Daytime sleepiness was categorized as never, rarely, sometimes, or frequent.

Questionnaires filled during recruitment were used to discover potentially influential factors, including age, sex, race/ethnicity, educational attainment, lifestyle, and weight.

Researchers looked at medical records and death registration data to track the health and survival of all the participants until the first diagnosis of glaucoma, death, emigration, or the end of the monitoring period (March 31, 2021) – whichever came first.

Researchers discovered that sleeping less than seven hours or longer than nine was associated with an eight percent increased glaucoma risk.

They also found while insomnia increased risk by 12% and snoring by four – daytime sleepiness raised that risk by 20 percent.

“In the analyses of sleep pattern, we found that compared with individuals with a healthy sleep pattern, a risk elevation of glaucoma was observed among individuals with snoring and daytime sleepiness,” the study authors wrote.

They also found that being a day or night person had no effect on glaucoma risk, and the results were similar when categorized by different types of glaucoma.

Kilkenny explained that there is a “multitude of reasons” why a person has poor sleep.

“First is taking sleep for granted,” he said. “Many people do not realize how important sleep is for good health. If one were never allowed to sleep, the person would die.”

Kilkenny said that too much caffeine can disrupt sleep, especially in the evening.

“The caffeine in tea and coffee is a stimulant that prevents you from sleeping well, especially when taken close to bedtime,” he cautioned.

He added that eating too late or eating close to bedtime could cause a full feeling in the chest and trigger heartburn, making it difficult to fall asleep.

Exercise and blue light can disrupt sleep

“Exercising too close to sleep time or even exposure to blue light from computer games and TV can disturb sleep if these devices are used too close to bedtime,” said Kilkenny.

“Stress is one of the most common issues,” he continued. “Everyday living can [be] stressful, which can interfere with sleep quality. We all need a period of relaxation in the evening to wind down before sleep.”

He emphasized that medical disorders such as insomnia, sleep apnea, and restless legs syndrome easily disrupt sleep.

“They are very common in the population and need to be treated by a physician,” said Kilkenny.

Oversleeping linked to poorer health outcomes

Kilkenny said sleeping more than nine hours a night is called hypersomniaTrusted Source and is associated with many medical conditions.

These include increased inflammation in the body, decreased immune function, and increased risk of chronic diseases such as obesity, depression, coronary heart disease, diabetes, and stroke.

“Combined, this leads to a 20 to 30 percent higher mortality risk than someone who sleeps the usual seven hours a night,” he said.

New research finds that poor sleep quality can significantly increase our risk of developing glaucoma, which can lead to blindness.

Experts say sleeping less than seven or more than nine hours is associated with various adverse health outcomes, including diabetes and strokes.

They also say stress is a common reason for poor sleep, and it’s important to have a period of relaxation before going to bed for healthy sleep.