Brief Answer: Refractive errors are commonest cause of headache Detailed Answer: Hello, Welcome to Health care magic The common ocular causes of headaches are Refractive error and inflammatory conditions of the eyes Uncorrected Refractive errors are the commonest cause of headache and it is because of fatigue of the muscles of the eye as the eyes tries to see the things clearly by squeezing the eyes, and because of repeated action of the muscles of the eye headache results. The treatment of the condition is by refraction and correction by spectacles. Dry eyes in the milder varieties are known to cause irritation of the eyes, but severe degrees of dry eyes can result in headache. The treatment of the condition is by using artificial tear eye drops. Hope In have answered your query. If you have any further questions I will be happy to answer. Thank you

---