Screen glare is one of the main reasons why we often suffer from eyestrain. If you are still using a CRT monitor, then consider switching to a flat LCD or LED monitor for your health. This will lessen your headaches and allow you to work longer without getting tired. Be sure to choose a matte screen so that it will not reflect light and hurt your eyes.
Another thing that you can do is to wear screen glare glasses. These have special coatings that allow them to minimize the glare that reaches your eyes. You can use them while inside the office to improve your workflow. You could also use them outside during sunny days. Ask your eye doctor for more information about them and get a pair made especially for you. It’s a great investment for your comfort and wellbeing.