Computer screens are starting to really bother my eyes

In the last couple months or so its been getting harder and harder to stare at a computer screen. Im not sure why but I guess in a way its a good thing, it will keep me away. It feels like My eyes are getting blurry and the words seem smaller to me. Maybe I just need reading glasses but I have been blinking a lot like I was told to and have been drinking water while on and still no help. I don't know how people can do it as a job or do it for more then 1 hour straight. Like when I use to play on the computer a lot i would always take breaks every moment I could so I have never had my eyes glued on for more then 45 min.