A variety of eye problems are associated with the onset of headaches. Squinting, straining, or pressure and swelling of the eye can all trigger pain in parts of the head. Common eye problems that can cause or contribute to headaches are described in more detail below.
Two main eye structures work together to focus images on the retina: the lens and the cornea. Sometimes, problems with the eye interfere with this focusing mechanism. The muscles then need to work harder, which can cause eye strain. Underlying conditions that can cause this to happen include the following:
Astigmatism – This refers to when the cornea is an irregular shape, causing objects to appear blurry. A person with this condition may then squint in order to focus on what they are trying to see, which can contribute to the onset of a headache.
Long-sightedness – The clinical term for long-sightedness is hyperopia. Here, an image is focused somewhere behind the eye instead of the retina . Nearby objects then appear blurry, meaning a person tends to squint in order to focus on them, which, again, can cause headaches.
Presbyopia – Here, the eye lens hardens as a result of aging, causing difficulty focusing, sore eyes and headaches.
These types of eye conditions can usually be corrected with the use of contact lenses or glasses.
Other causes of eye strain include any activity that requires intense use of the eye for long periods or in difficult conditions such as reading, writing, driving and straining to see in dim light.
Digital device screens such as computer monitors and Smartphones are a common cause of eye strain . People who look at these screens for more than two hours at a time, every day, are the most likely to experience eye strain. Looking at a computer screen is more likely to strain the eyes than looking at printed material because people do not tend to tend to blink as much while using a computer screen, which helps to keep the eye moist. There is also poor contrast between the background and text and the screens give off glare or reflection.
If a person suspects they have eye strain, they should have their vision checked by a qualified professional. People who already wear glasses or contact lenses may be unaware that slight changes have occurred over time and these individuals should attend eye appointments regularly to check that no updates are needed to their lenses or glasses.
Glaucoma causes increased pressure in the eye leading to damage of the optic nerve . This then leads to loss of vision because the optic nerve carries information to the brain. A fluid called aqueous humour, which usually plumps up the cornea, builds up due to a blockage in the drainage area at the back of the eye. This leads to increased pressure that can damage the optic nerve and lead to severe headache, blurred vision, vomiting and watery eyes. Glaucoma cannot be prevented, but proper treatment can slow its progression. It is therefore essential that the disorder is medically investigated.
Papilloedema refers to swelling of the optic disc as a result of increased intracranial pressure. A number of conditions can cause this to happen including a swelling, hemorrhage or tumor in the brain. Aside from head pain, the person may experience double and blurred vision, although sometimes no symptoms develop. If a headache results, it may be more intense when coughing or sneezing and less painful when lying down.