A few weeks ago I got new glasses. I needed them; my cockatoo has made so many beak marks on the lenses of my old bifocals that trying to see through them is like looking through fog.
So, off I went, and when the optometrist wrote up my prescription, I asked her to write a second one, for glasses to be worn specifically for working on the computer. I spend 8-10 hours daily on the computer, and it seemed like a wise investment.
Well, it was. After four weeks of wearing my computer glasses, I find my eyes are less strained at the end of a day, and I have fewer headaches.
What are computer glasses? They're like reading glasses, a prescription for a single focal length that focuses on the computer screen. Unlike with my bifocals, I don't need to keep moving my head around to get a clear focus on my computer monitor. Everything beyond that distance, of course, is out of focus. But I can switch back to the new bifocals when I'm not actually working on the computer.
In addition, I kept my old glasses, and I wear them when the cockatoo is out and about; he can't do more damage to the old lenses than he already has. So just as I have "computer glasses", I also have what I call my "parrot glasses".
So, if you wear glasses (and especially if you're at the age where you start needing bifocals), my experience might be of benefit to you. Cheers!