Refractive errors — or problems with the focusing of light by the eye — can be the cause of persistent tension-type headache. Uncorrected refractive errors cause problems with visual acuity, making things blurry and unfocused. As your eyes attempt to compensate for the vision deficit, forehead and scalp muscles contract excessively, especially with squinting, and headache can result.
And because the focusing ability of the eye decreases with age, the problem becomes more common as you grow older. The good news is that this type of headache is usually easily corrected with glasses, contact lenses, or corrective laser surgery.
Eyestrain, or asthenopia, can also cause a dull, frontal headache. People who work at computer screens for long periods of time or do a lot of “close work” often experience this type of visual fatigue. Sometimes this is associated with uncorrected refractive errors. Rest and properly prescribed eyeglasses are often helpful.
Diseases of the Optic Nerve
The optic nerve connects the back of the eye to the brain and is responsible for transmitting visual images in the form of nerve impulses from the retina to the brain. When the nerve is damaged by pressure or inflammation, vision distortion and/or loss can occur. Headache, especially in the region of the affected eye is a frequent symptom of diseases of the optic nerve.
Glaucoma is a visual disorder characterized by optic nerve damage resulting from elevated pressure within the eye that can result in partial to complete vision loss. Both headache and eye pain are warning signs of severe elevation of eye pressure and are an indication for immediate treatment by an ophthalmologist.
Retrobulbar optic neuritis is caused by inflammation of the optic nerve. The condition can be caused by viral infections and has a strong association with multiple sclerosis, a disease of the central nervous system. Head pain focused around the eye is a common feature, especially at the extremes of movement of the eye within the eye socket.