Eye testing can pick up a bunch of stuff early, so regular eye tests (especially when you get older) are important.

Don't forget that in England your employer makes a contribution to the cost of eye-tests and glasses if you're a monitor user.

(http://www.direct.gov.uk/en/Employment/HealthAndSafetyAtWork...)

Plenty of pages that get linked to from HN are pretty bad for readability - awful contrast or weird font choices. User side CSS is nice, but it's a shame to have to fix so many sites.