Glaucoma is a disease of the eyes that can cause headaches. Fluid in the eye does not drain properly, or there is over-production of fluid, which causes increased pressure within the eye. Prolonged increased pressure can lead to visual loss if not corrected.

The headache caused by glaucoma may be felt in or around the eyes or the forehead, and vary in intensity from mild to severe. Nausea and vomiting also can accompany the headache.

Some forms of glaucoma are sometimes mistaken for migraine. A correct diagnosis can be made by measuring the pressure in the eye. People suffering from glaucoma may experience a fogging of vision or see colored halos around objects. Many drugs, including certain over-the-counter medications such as antihistamines, can worsen untreated glaucoma and must be avoided. Be sure to tell your healthcare provider if you have glaucoma, especially prior to taking any new medication, including headache preventive therapies.