The causality between headaches and dry eyes is not determined but the two are definitely correlated.
Studies have found a link between dry eyes and migraine and headaches are a migraine symptom. Dry eyes can worsen the migraine symptoms thus can lead to a more painful and intense headache.
Although other symptoms such as itchiness, blurred vision, and inflammation are more common to occur in dry eye syndrome patients, headache can also be a symptom.
There is not enough research available to find out the exact connection between the two conditions. It is not known if headaches are a symptom associated with dry eyes or if headaches cause dry eyes. Both conditions can occur for a number of reasons. Medication is one of them. The active ingredient found in many acne treatments can trigger dry eyes and headaches as a side effect. If you experience DES and headaches, it’s best to get a medical examination to determine the cause. In some cases, dry eyes treatment has positive effects on headache as well.