Study: Sleep deprivation can cause blindness

Too little sleep, daytime sleepiness and snoring may be associated with an increased risk of glaucoma, a leading cause of blindness that research shows will affect 112 million people worldwide over the next 20 years.

According to Sky News, glaucoma is characterized by progressive loss of light-sensitive cells in the eye and damage to the optic nerve, which can lead to gradual vision loss if the disease is left untreated. A study published in the journal BMJ Open found a number of reasons why poor sleep and glaucoma are related.

First, internal eye pressure, a key factor in the development of the disease, increases when a person lies down and when sleep hormones go out of whack.

Depression and anxiety, which often accompany insomnia, can also increase this pressure because they can have a negative effect on the regulation of cortisol production: the body's main stress hormone.

Repeated or prolonged episodes of low cellular oxygen levels caused by sleep apnea (when breathing is interrupted and resumed during sleep) can also cause damage to the crucial optic nerve.

Everyone who took part in the study was between the ages of 50 and 69, and they were recruited from 2006 to 2010. Participants included people who described themselves as midnighters, suffering from insomnia, daytime sleepiness and excessive snoring.

A total of 8,690 cases of glaucoma were identified over an average of 10.5 years of follow-up for 409,000 people.

People who slept less or more than usual were 8% more likely to have glaucoma, 12% more likely to have insomnia, and those who often suffered from daytime sleepiness were 20% more likely to have glaucoma. For those who snored excessively, the risk was 4%.

The researchers say the results underscore the need for sleep therapy in those at highest risk for the disease and vision testing to detect early signs of glaucoma.

Follow NEWS.am Medicine on Facebook and Twitter