Did you know that most humans spend between a quarter and a third of their lives sleeping? Furthermore, according to team of South Korean researchers, your sleeping position could have a major impact on your eye health.

Under Pressure

This team’s work, which appeared in the March 2014 issue of American Journal of Ophthalmology, identified common sleeping patterns among those with worsening glaucoma. Specifically, these individuals tended to sleep with the affected eye facing downward.

A total of 430 glaucoma patients agreed to participate in the study. Nearly a third (132) of these subjects typically slept on one side of their body, of which 67 had their glaucoma-affected eye pressed against their pillows during sleep. Such habits are likely to be detrimental to the eye health of glaucoma sufferers, as the additional pressure causes the eye to deteriorate at a faster rate.

Too Much Tension

To further test this hypothesis, the team also compared those with normal-tension glaucoma to volunteers with high-tension glaucoma, a form of this condition marked by elevated pressure within the eye. They found that 71 percent of those in the high-tension glaucoma group slept with their bad eyes facing downward, whereas 66 percent of the former did the same. By itself, the report does not conclusively prove that the body’s position during sleep intensifies glaucoma symptoms. However, the authors do note that their work does show that that a connection exists “between the preferred sleeping position and asymmetric visual field loss between eyes.”