I stare at a computer screen all day, and this strains my eyes. After about a year of doing this, I noticed that my eyes were having trouble adjusting when I looked from the screen to something far away. This made everything sort of blurry.
In addition to that, it made me really dizzy. I felt like I was losing my balance, because my reaction was delayed. I had to go to the eye doctor.
He gave me some corrective lenses to wear. They have made all the difference. I really needed some sort of vision aid because of the nature of my work, and I think that going to him may have saved my eyesight.