NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Eyesight dangers using telescopes
From: Douglas Denny
Date: 2009 Jun 30, 01:54 -0700
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. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---