I would advise you to get your eye number test as it may cause headache. Also I would like to know from you if  are you using any reading glasses for your work. My suggestion for you would be to blink your eyes frequently. If your working for long hours , follow 20 20 20 rule that is after every 20 minutes take a break for 20 seconds and look far as much as 20 feet if possible . Also you can put ice pack at night over upper eye lids to soothe. You can also use artificial tear drops 6 times per day till your work continues.

Hi .. Read and Follow advice about computer vision syndrome . Check for change in numbers. Use lubricating drops like Refresh liquegel 3/4 times . If not better..look for other causes too like migraine.