text: can you tell me what the connection is between very bad headaches and my doctor telling me to get my eyes test   eye strain due to a deterioration in vision causes headaches. so go and get your eyes tested to find out whether you should be wearing glasses. if you do, wear them and see if the headaches improve after a few weeks and if they don't you can go back to your doctor then. and if you don't need glasses then you can go back to your doctor, but eye strain can cause really bad headaches.