Many eye problems are linked to the onset of headaches. Squinting, straining, or pressure and swelling of the eye may cause pain in parts of the head. The following conditions can be corrected with the use of glasses or contact lenses.  

Eye strain

The lens and the cornea work together to focus images on the retina. Sometimes, eye problemsaffect this focusing mechanism. This makes the eye muscles to work harder causing eye strain.  

Astigmatism

Objects appear blurry when the cornea is an irregular shape. A person with Astigmatism may squint in an effort to focus on what is in front of them contributing to the onset of a headache.  

Long-sightedness

Hyperopia is the clinical term for long-sightedness. In this condition, instead of the retina, an image is focused somewhere behind the eye, making nearby objects appear blurry. A person may squint in order to focus on them, again, causing headaches.  

Presbyopia

An age-related process, differing from Astigmatism or long-sightedness, the eye lens hardens as you age, causing difficulty focusing, sore eyes and headaches.  

Other reasons for headaches are

Intense use of the eye straining to see in dim light, or long periods of reading, writing, driving, may give rise to headaches related to eye-strain.  

Digital Devices

Looking at smartphones, tablets, and computers for more than 2 hours a day causes eye strain in many people. Blinking frequently keeps the eye surface moist. But people looking at a computer screen are more likely to strain the eyes as they do not tend to blink as much while using a computer screen. The screens also give off glare or reflection - increasing the eye-strain and resultant headache.