Not wearing prescription glasses when needed can directly cause headaches. This pain is a common symptom of asthenopia, or eye strain, resulting from uncorrected vision. The discomfort arises because the visual system must work harder to achieve clear focus, straining the muscles both inside and outside the eye.
The Mechanism of Visual Strain
The human eye relies on an intricate muscular system to manage both focusing and alignment. When a refractive error exists and glasses are not worn, the eye’s internal focusing muscle, the ciliary muscle, must constantly contract to adjust the lens. This continuous, involuntary contraction attempts to compensate for the inability of the eye to properly focus light onto the retina.
This intense, prolonged muscular effort leads to fatigue. The extraocular muscles, which control eye movement and alignment, also become overworked as the brain tries to fuse two slightly different images into one clear picture. This persistent over-exertion of both sets of eye muscles results in tension and pain that radiates to the surrounding areas of the head.
Types of Headaches Related to Vision
The head pain associated with uncorrected vision is most frequently categorized as a tension-type headache. This type of pain is generally described as a dull, persistent ache rather than a sharp or throbbing sensation. It is commonly located in the forehead, around the temples, or directly behind the eyes.
A distinct feature of these headaches is their timing, often appearing or worsening after periods of intense visual concentration. Activities like reading, prolonged computer use, or driving can trigger the pain as the day progresses and the compensating muscles grow more fatigued. Unlike some other headache types, this pain is typically absent upon waking, because the eye muscles have rested overnight.
Specific Vision Problems That Are Culprits
Several specific refractive errors are particularly prone to causing headaches when they remain uncorrected. Hyperopia, or farsightedness, is a major culprit because the eye must constantly focus, even to see distant objects clearly, due to the light focusing behind the retina. This persistent need for accommodation forces the ciliary muscle into an ongoing state of tension.
Astigmatism, which is an imperfection in the curvature of the cornea or lens, causes light to focus unevenly, creating blurred or distorted vision. The brain and eye muscles strain to resolve this blur, which results in significant eye fatigue and subsequent headaches. Similarly, presbyopia, the age-related loss of near focusing ability that typically begins after age 40, forces individuals to strain heavily for close-up tasks like reading small print.
When to Seek Professional Guidance
While most headaches from uncorrected vision resolve once glasses are worn, regular comprehensive eye exams remain the most reliable way to prevent this discomfort. A new or updated prescription may temporarily cause a mild headache as your eyes and brain adjust to the correct focusing power. This period of adaptation is normal and typically brief.
You should seek prompt professional attention if a headache is sudden and severe, or if it is accompanied by other serious symptoms. These symptoms include:
- Sudden vision loss
- Double vision
- Intense eye pain
- Flashes of light
Persistent headaches that do not improve with rest or pain relievers, even after your vision has been corrected, also warrant an immediate evaluation to rule out other underlying health conditions.