Joe, Interesting but I need corrective lenses so I'm happy with mine. Also my elevation is only 1100 feet.
BTW I have a 14" Meade telescope though viewing here is somewhat obstructed by all the trees around. I've thought of putting it on a platform on top of my house which would greatly improving viewing even with the addition of some heat distortion but haven't gotten around to it... Best, Edgar On Nov 24, 2012, at 1:11 PM, Joe wrote: > Edgar, > > Long ago I sought a great solution for UV and light filtering in bright > conditions, in the deserts and high mountains where we carry out our > observing at telescopes. > > Our "day" there is not just "nighttime": we have tasks to do in sunny hours, > too. Sleep hours are fewer than on sesshin. There's lots to do in the bright > of day; and some of it may be recreational, up there. Certainly for exercise. > > I don't need corrective lenses, so I looked for off-the-shelf "shades", but > those for use in climbing. The glacier-climbing glasses seemed to be the best > optical "fit", for my hopes. So I tried the Julbo brand. This French outfit > has been at it since 1895, and are pretty well respected; scans of the light > filtration are available (not that we don't have technology to do that > ourselves, but it's nice to have assurance up-front that the product may > suit). > > See a low-cost entry in their catalog. I use a polarizing pair, but the > "Sherpa" model has lenses that are even a little darker. The supple leather > side-shields are effective in blocking what's called "fugitive-light". That's > a very needed provision when a lens is so dark as these, because, when > wearing them in bright conditions, the iris opens, and any fugitive light > from sides, bottom and top can still enter the eye -- even if not to strike > the retina -- powerfully, and begin the polymerization process of the lens of > the eye, leading to nuclear (or worse) cataracts that we hope to avoid. > > For my use of these glasses, I carefully spray-painted the removable > side-shields WHITE on their outside: who needs the extra heating when it's > 115 degrees in the desert, downtown? Cooler up the Hill, though. The > adiabatic lapse-rate of temperature is about 5 deg F for every 1000 ft of > rise: a good rule-of-thumb. ;-) > > Yes, please see the inexpensive (and great) Julbo Sherpas: > > http://www.rei.com/product/826294/julbo-sherpa-glacier-glasses,-black,-smallpectron-3-plus?preferredSku=8262940001&cm_mmc=cse_froogle-_-pla-_-product-_-8262940001&mr:trackingCode=5C3F4BBC-FB91-E011-9A77-001B21631C34&mr:referralID=NA&mr:adType=pla&{copy:s_kwcid}=&gclid=CODyluSU6LMCFUjZQgodXV0AjA > > They stay on your face, too: curve-ended stems hold them on comfortably, a > feature that's really a necessity if you do any climbing. Great for biking! > > This post is on-topic because these dark glasses are good for Zen students > doing kinhin outdoors with the group on sesshin, some days in, when the eyes > may be a little more sensitive. > > To LOWER the sensitivity of the eyes, just eat less of the medicinal or > dietary Potato Leaves! > > All best, > > --Joe > > > Edgar Owen <edgarowen@...> wrote: > > > > Joe, > > > > My standard pair of glasses has polycarbonate lens which block almost all > > UV much better than sunglasses. > >
