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Polarized sunglasses, as with other type of sunglasses may not block enough UV to be considered safe. From WikiPedia: for adequate protection, experts recommend sunglasses that reflect or filter out 99-100% of UVA and UVB light, with wavelengths up to 400 nm. Sunglasses which meet this requirement are often labeled as "UV400. In other words, you ...


11

In Europe your will be hiking on altitudes less than 5000 m, and on these altitudes you can go with sunglasses without heavy specialized equipement. However not any piece of sunglasses will do. First, they have to be either made of glass (which stops UV rays) or special UV-proof plastic. Not every plastic stops UV rays, and if not, using it is even more ...


11

When I first planned my trek in Himalays I was suggested to keep my Gogs and Glares with me when I am outdoor-bound, in snow. A good article in my Adventure related Database rtf files says: Hours of bright sunlight can burn the surface of the eye, causing a temporary but painful condition known as Photokeratitis. Over time, unprotected exposure can ...


11

Polarization and UV protection on sunglasses are two different things. While UV refers to light of a wavelength of approximately 10nm to 400nm, light of any wavelength can be polarized. Sunglasses with a polarization filter block light, that is horizontally polarized (e.g. light reflected on water). This has no specific effect on UV-light. So polarized ...


10

The problem is that eyeglass prescriptions are calculated for a standard distance between the lens and the eye, with the lenses in flat frames parallel to the face. You can see the effect of varying lens-to-eye distance simply by pushing or pulling on your conventional eyeglasses, and the effect of angle by tilting them on the bridge of your nose. Your ...


10

Background Due to the very nature of light and lenses it is impossible to not have depth perception change when looking through a lens. The light will pass through the first surface of the lens, slow down (plastic is denser than air), hit the principle axis and then exit the second surface of the lens and converge at the focal point. What you are seeing at ...


8

A clean sock will protect them from scratches with no need for fasteners and it takes a fair bit of pressure or impact to actually damage glasses (bending them slightly is another matter). Once wrapped they can go in the top of your pack or any pocket.


8

Those types of glasses do not provide adequate protection from sunlight, especially in areas with lots of reflective surfaces (desert, snow) and at high elevations where there's more UV radiation due to the thinner atmosphere above you. What you want are either wrap-around glasses which don't let light in the sides, or particular glasses called "glacier ...


8

According to article Benefits of Copper, Orange, Yellow And Brown Lens Tints and from my own experience, but with cycling solar glasses: Copper, orange, yellow/amber and brown lens tints make an environment appear brighter and are commonly used in low-light conditions. These lens tints significantly block blue light and enhance contrast and depth ...


7

These are generally known as glacier glasses. They are rated as Category 4 on the CE scale and you aren't supposed to drive while wearing them. Sunglasses in Category 4 only transmit 4-8% of available visible light. Hidalogos sunglass guide has a very complete list of the different factors in choosing sunglasses. Category 4 come in a wider range of ...


6

I own only glacier glasses and use them as sunglasses as well (I take off the "blinders"). If you decide to go with sunglasses only, make sure they offer proper UV protection (not all of them do). Reasons as explained by @WedaPashi (I'd only add that while cataracts can be operated IMHO that is no reason not to try and avoid them).


6

For the scenario, no backpack, no nothing, just a short hike and you find your treasure shining in the sun. Find a piece of grass that won't break easily and can be bended without breaking in segments Put one arm of the glasses through a belt loophole on your jeans. close the glasses Wrap the grass over the arms of the glasses to prevent them opening up and ...


6

I'm an extremely nearsighted person who has trouble with contacts and spends a whole lot of time being active outdoors. As a result, I've done a lot of investigating into prescription sunglasses, and tested several pairs. The biggest difference between sunglasses and regular glasses is that sunglasses need to block out a larger area than a regular glasses ...


6

I like the idea of glasses that change from sunglasses to indoor Photochromic lenses are a lot less useful than most people think when they hear about the concept. The main problem is that the change takes time - about a minute to darken and nearly five minutes to un-darken. That makes them basically useless for things like tunnels. Another problem is that ...


6

Blue may be somewhat more likely to let UV through if they are poor quality. Most sunglasses now carry some form of label regarding UV blocking. In photography, you often use an orange or red filter to increase the effective contrast between sky and cloud, or rock and vegetation. These filters also reduce the effect of haze, which is biased toward the ...


6

Blue light can injure the eyes. Is there any reason to avoid blue lenses? Will I do more long-term damage to my eyes than choosing another option like these? UV light (which is blocked by good sunglasses) can cause photo ceratitis and conjunctivitis (inflammation of the cornea and/or the conjunctiva), but it doesn't penetrate deeply into the human eye as ...


5

Any sturdy box big enough to hold them would work, also when the box is a lot bigger. You can fill the empty space with something soft, like a piece of clothing you happen to have handy. The smaller (but still big enough) your box is, the more snug your pair of glasses will sit. In a sturdy box you can put your glasses in any kind of bag. When you do not ...


5

There are actual standards for this. If you are going somewhere where snow blindness is a real possibility, you should have sunglasses that meet the standard. The most common standard used in outdoor sunglasses is the Category standard based on the european CE standards. There are 5 categories 0-4 This page has a good overview: An Explication of ...


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Safety glasses would presumably meet some safety standard, for example impact resistance, and the standard so meet would be cited. Shooting glasses might offer some impact resistance (or other protection...), but wouldn't have to meet the standard.


5

This did indeed happen to Robert Swan, who is the first man in history to walk to both the South and North Poles. His eyes turned from dark blue to light blue on his trek to the South Pole, which began in November of 1985 and ended at the Pole in January of 1986. (His trip to the North Pole was in 1989.) There are very credible sources, but the best one is ...


4

The sides on glacier glasses are invaluable when on a snowfield, as the sheer amount of light hitting your eyes is increased dramatically by the high reflection from the snow. Ordinary sunglasses allow a lot of light to hit your eye from all sides. I would recommend always using the sides when on snowfields.


4

Hockey players have the same problem and will use specialized products, but many find rubbing the lens (inside and out) with shampoo works just as well and is much less expensive.


4

Paul and Kevin are correct here - any corrective lens has to alter what your eye sees. Your brain very rapidly corrects (a few minutes) but it is a basic function of optical physics that is unavoidable. It's not because of two layers of glass, it is the correction process - you are changing the light path. I would suggest that if you need the corrective ...


4

I won't discuss the aspects that the other two answers have covered well. I am very near-sighted. For my non-sunglasses, I have what are called "progressives". I think this is what you are calling bi-focal, multi-focal. For my sunglasses, I skipped the progressive feature, which I don't find very useful anyway. Outdoors, I am focused on distance almost ...


3

The dark tint isn't required for UV blocking. That's not to say it's not a good thing to have. Many plastics have strong UV absorption, and some safety glasses have an additional coating. For blocking UV lasers this has been tested, though UV laser glasses are often a pale straw colour. Many safety glasses actually have UV protection anyway. There are ...


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