People with obstructive sleep apnea syndrome are prone to suffer from glaucoma at rate about 10 times higher. Study found optic nerve could be damaged due to hypoxia without a spike in eye pressure. Glaucoma is thought to be a disease in which the optic nerve sustains damage due to increased eye pressure, resulting in restricted visual field. “However, it has been technically difficult to measure eye pressure. We employed a special sensor akin to a contact lens to monitor pressure changes when OSAS patients’ breathing repeatedly stopped during sleep,” said Yasuhiro Shinmei, Hokkaido University.