They can have many different causes. Sometimes, but not usually, eye problems are a cause. The most common cause of headaches is scalp and neck muscle contraction. Tension, anxiety, strain, stress, fatigue, and depression may all bring about sudden or gradual muscle contraction and pain. Migraine headaches are another common type of headache.
Migraines are usually much more severe than muscle contraction headaches.
They are caused by changes in the blood vessels and blood flow in the head. Headaches can also be caused by many diseases and disorders affecting other parts of the body. For example, ear problems, jaw problems, sinus problems, arthritis, high blood pressure, nerve diseases, and even tumors can cause headaches. Rarely, eye problems cause headaches. For example, if you need reading glasses and read for a long time without glasses, or with glasses that are too weak, you may develop eye strain and a headache.