Headaches are extremely common, and in many cases, an undetected vision problem is the underlying cause. If you are experiencing frequent headaches — particularly after reading, using a screen, or concentrating on close work — an eye test should be one of your first investigations.
The most common vision-related cause of headaches is uncorrected refractive error. If you are slightly long-sighted (hypermetropic), your eyes work harder to focus, especially on close-up tasks. This effort can cause eye strain headaches that tend to build during the day and are worst after sustained concentration. Similarly, astigmatism (where the cornea has an irregular shape) causes your eyes to struggle to form a sharp image, leading to strain and headaches. Even a mild prescription that you did not know you needed can be enough to cause persistent headaches.
An outdated or incorrect glasses prescription can also cause headaches. If your prescription has changed since your last test, your current glasses may no longer be providing optimal correction, forcing your eyes to compensate and causing strain. This is particularly common in people who have not had an eye test for several years.
Digital eye strain (also known as computer vision syndrome) is another major cause of headaches related to vision. Prolonged screen use reduces your blink rate, leading to dry eyes and strain, while the constant focusing effort on a screen causes muscular fatigue around the eyes. Symptoms typically include headaches at the front of the head or around the eyes, dry or watery eyes, blurry vision, and neck or shoulder tension.
Less commonly, headaches can be associated with more serious eye conditions. Acute angle-closure glaucoma causes sudden severe headache with eye pain and blurred vision — this is a medical emergency. Raised intracranial pressure can cause headaches with visual disturbances such as temporary blackouts or double vision. If your headaches are severe, sudden, or accompanied by visual symptoms, seek immediate medical advice.
An eye test is a quick, painless, and inexpensive first step in investigating headaches. Many people find that a simple pair of glasses resolves headaches they have been experiencing for months or even years.