I spent someof last year's tax refund on a new pair of glasses. After 5 years the old ones just weren't doing the job so well, and the nickel in the frames was being corroded by skin acid, causing annoying little pits in the once smooth frame. The new pair are slightly stronger and have polycarbonate lenses that tint in sunlight, with titanium frames. I've lost that little bit of strangeness that my old glasses had when they darkened to noticably different colours. That used to freak people out.