You may have computer vision syndrome from spending way too much time staring at a computer screen! A great idea is to have a screen attached to your computer which reduces the glare.
Try changing the distance your screen is from you, and even it’s angle. Lighting is another important factor! Have an eye test yearly to see if your eyes are deteriorating, and please, please , please get rid of those old tube style monitors and replace it with a computer or laptop with an LCD screen, which is easier on the eyes!