A sleep disorder could not only make people tired in mind and body - it can affect their vision too, according to new analysis.
Obstructive sleep apnoea (OSA) is linked to high blood pressure, which in turn can affect the complex vascular system of the eye.
Examination of the results of several studies has led pulmonologist and sleep specialist Dr E Andrew Waller from the Mayo Clinic to draw up a list of eye complaints potentially caused by OSA.
These include floppy eyelid syndrome, glaucoma, non-arteritic anterior ischemic optic neuropathy and papilledema.
Mr Waller said: "The mechanisms that link these disorders is minimal.
"However, the recognition of these associations is important for primary care physicians, ophthalmologists and sleep physicians."
He went on to say patients suffering from OSA should get regular eye examinations to monitor the potential onset of glaucoma.
People with OSA may find they wake several times during the night. The condition affects twice as many men than women.
by Adrian Galbreth