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    Re: Eyesight dangers using telescopes
    From: Douglas Denny
    Date: 2009 Jun 30, 01:54 -0700

    Dear Mr Gebhart
    You ask for simple answers.
    My answers would be:
    1. No.  Since Crookes published his work on eye damage to high flux levels of 
    I/R and U/V, the solution has been available - providing correct filters 
    (shades)are used. Exposure is for short periods using a sextant. Welders and 
    glass-blowers are more at risk.
    2. Yes.  Despite the downgrading of the potential of risk by some here, eye 
    damage is significantly increased with use of telescopes.   Use of 
    filters/shades eliminates this risk.
    We live in a litigious socety now where any responsibility for injury becomes 
    actionable. I am not in the least bit surprised if there is some law, 
    directive or rule about manufacturing something which is potentially 
    injurous. In the EU here in Europe it is usually the manufacturer's 
    responsibility to prove his product is not injurious before he can market it, 
    (like the chemicals directive or 'alternative' health products/supplements 
    for example) - which can be impossible and/or hugely costly.
    Douglas Denny.
    Chichester.  England.
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