Hello.
If you use the computers for a long period of time, you might have to check your eyesight for any refractive errors. The screen also needs to be soothing to the eyes. Looking at the computer screen for a long period tenses the forehead muscles (those above the eye brows), and may lead to the headache.
You may also need to make sure you drink adequate water/fluids. Mild dehydration is the commonest cause of headache.
Coffee and tea have elements that can help relax the muscles. They may help temporarily, but their effectiveness may decrease over a period of time.
You can consult a general physician regarding this, to rule out any physical causes. If you have had migraine headaches earlier, you are more prone for headaches due to the factors we discussed above. Removing the causative factor or modifying them appears to be the best way out.
Hope this helps.
Abhijeet Deshmukh, MD
(This post is for the purpose of providing medical information and is not a substitute for a face-to-face consultation with a doctor. This post is not intended to give or rule out a diagnosis, create a doctor-patient relationship or replace an existing one. I am not able to diagnose medical conditions online. Please consult with your doctor or a qualified healthcare provider for diagnosis and treatment options)