Use it or Lose it (Score 1)

I've been staring at computer screens for more like 25 years myself (no congratulations necessary ;) ). Certainly, I've experienced some pretty weird optical things in that time, although my vision is still very good. For instance, when I started full-time IT work about 7 years ago, I was pulling 16 hour days fairly consistently. Even though I'd had pretty heavy computer usage before that job, for about the first 3 weeks into the job, I'd walk outside and find my perception (not vision, I think, but probably more the way my brain was processing the optical input) was oddly distorted... I remember walking around a local shopping mall and seeing everything like it was a computer network. Trippy! (and I wasn't even smoking anything at the time). It also meant that I used to walk around outside for about half an hour before driving, as my distance perception wasn't so hot until I re-adjusted. I find this happens even today - if I've had a long stint writing code (ie. minimal or no social interaction for 5-10 hours), when I go outside, it takes my other cognitive faculties a while to "switch on". The point in relation to your original post is this: Actual physical optical limitations aside, the brain in almost every way operates on a "use it or lose it" basis. The reverse is also true - which is how we develop a high level of skill in something, or indeed habitual behaviour (based on recent cognitive psychology research). An optician told me once that it's a good idea to deliberately use your long distance vision for about 5-10 minutes for every hour of computer usage. As any decent programmer will know, sometimes those hours pass without one's noticing! A little exercise I've developed to get around this, which I find has helped immensely, is to go and hang out my street-facing window (I work from an apartment) at the end of the day and watch the pretty girls walk past on their way home. Cheesy, I know, but it works for two reasons: a) There is an inherent motivating factor ;) b) The process of focussing on a moving "target" is more cognitively complex than, say, just looking away from the computer screen every once in a while. Having something specific to look at, over a long distance, seems to train the eye muscles much better. As a result, I've had far less eye strain (which I used to notice when finally going to bed), and a reduced "re-integration" effect time when I go out for lunch or whenever. Hope this helps :)