On 5 November 2014 05:52, Herbert Graf wrote: > > My grandmother came home from the store one day, complaining that it > felt like she had sand in her eyes. Upon interrogation, she did recall th= at > there was a welder performing repair work some ~ten meters away, as she > waited in line. > > The safety standards were quite lax in the post-collapse USSR. > > OMG?? Was she OK after that? > > She as probably OK again in a week or so. Eyes seem to be quite tough. UV burn heals without apparent long term damage in most cases, but can be from annoying to very very painful. Seems to typically last 1 to 2 weeks. Common examples are snow-blindness and arc-eye. Persisting at the activity or having a long intense session before the effects struck may be more damaging. I've had enough "snow blindness" to really regret it the next day after a long day out on snow with no ski goggles most of the time. 'Experience is what you get when you don;t get what you want.' I've watched quite a lot of gas and metal arc welding over decades on a casual basis and never had any noticeable effects. In my wife's case I did a lot of reading to see if it seemed likely that the retinal damage they found was possibly associated with my UV lamp. Both several hospital specialists and a private specialist (usually same people recycled at higher rate) were adamant that the UV did not cause the retinal damage. My extensive reading at the time persuaded me that there was a small but significant possibility that it was the cause and that they did not usually get people with such pure high intensity continuous sources. The literature had a few cases with intensive sources that were likely caused by UV and most specialists rejected those "out of hand" due to lack of "big picture" input. Google truns many amateurs into dangerous medical pseudo-specialists BUT also enables careful investigators to know things that world class specialists know but most doctors don't. [[eg I have 'Gilbert's syndrome' (high level of unconjugated serum bilirubin due to incomplete red cell breakdown due to genetic anomaly. Most doctors and mine hold the very long held view that it is benign and of no effect. My belief that it is significantly "heart protective" is met with imperfectly concealed disdain by my doctor. Evidently he does not spend his spare time studying now decade+ long available and ongoing metastudies of obscure conditions in top class medical journals. One does not expect them to do so - but needs to be aware that most don't.]] My wife's eye damage that was known to be related was unexpected, so probably came either via reflection or refraction at an unexpected angle via the edge of lenses - so she could have been exposed to the semi focused source for seconds to minutes. The tube is simply a 15W? fluorescent but with nothing to fluoresce - just an impressive column of ionised mercury vapour which you KNOW you don't want to look at for more than second or few. I have glanced at it for perhaps 1 to 2 seconds per time on various occasions over many years when eg positioning things under and near it and I've never noticed ill effects. Russell --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .