воскресенье, 18 ноября 2007 г.

Polarized lenses

Polarization is like a chemical venetian blind which rearranges light and lets you see "through" glare. 100% Polarized lenses are the only truly effective way of eliminating glare. Water, fog, rain, snow or early morning dew, have reflective properties, which enhance reflected glare. In addition to water, glare is also a problem on roads and highways.

For years, boaters and fishermen have used polarized sunglasses to reduce glare from the water that they spend so much time on. In the past few years, however, the benefits of polarized sunglasses have been realized by a variety of other outdoor sports enthusiasts as well as by drivers and general use wearers. The popularity of polarized lenses has increased dramatically, as has availability.

Besides boaters, people that benefit most from polarized sunglasses include skiers, golfers, bikers, and joggers, who enjoy a clearer view and elimination of glare.

These sunglasses can be used for driving and in fact can reduce the glare that comes off a long, flat surface such as the hood of the car or the surface of a road. Polarized sunglasses can also be used indoors by light-sensitive people such as post-cataract surgery patients or by those exposed to bright light through windows.

How Do Polarized Lenses Work?
Light reflected from surfaces like a flat road or smooth water is generally horizontally polarized. This horizontally polarized light is blocked by the vertically oriented polarizers in the lenses.

The result: a reduction in annoying and sometimes dangerous glare.

There is some debate on the effects of polarized lenses on snow-covered surfaces. Some experts say they can reduce the intense glare that is caused by sunlight reflecting off snow. Others purport that the lenses are not satisfactory for sports such as downhill skiing because they may not provide the contrast the eye needs to distinguish ice patches or moguls.

In addition, polarized lenses may also react adversely with liquid crystal displays (LCDs) found on the dashboards of some cars or in other places such as the digital screens on automatic teller (bank) machines. The problem with LCDs is that when viewed through polarized lenses from a certain angle, they can be invisible.

However, for most other sports and activities, polarized sunglasses can offer great advantages. And today, many types of polarized lenses are available on the market.

Polarized progressive lenses are perfect for the presbyope who is also an outdoor sports aficionado. And polarized photochromic lenses, which change from dark outside to light inside, are right for the light-sensitive person who changes environments frequently (inside to outside and vice versa).

Whether you spend your time boating or waterskiing, in-line skating or mountain biking, driving or jogging, polarized sunglasses are an excellent choice.

Why (fisher)men prefer them polarized?
Because they are more FUN when the SUN is up !!!

Fact: The glare of the sun on the sea (and other surfaces) is highly polarized !

Indeed, the glare can be almost completely horizontally polarized, depending on the height of the sun. In addition, all reflections from objects above water are partially polarized. With polarized sunglasses the sea appears more transparent! The image to the left was taken through a polarizer with its transmission axis oriented horizontally. The image to the right was taken through a vertical polarizer. Which one would you like to use for fishing?

Surf through horizontal polarizing filter
Surf through vertical polarizing filter

This is just one more example of polarization by reflection. Although the light from the sun is not polarized, it can be separated into two polarized components that are reflected and transmitted in different amounts by the surface of the water (Fresnel laws). More of the horizontal component will be reflected than the vertical component, thus partially polarizing the reflected light (except if you look at a glancing angle or straight down).

Fisherman Sunglasses
The polarized sunglasses used by fishermen have polarized filters with the transmission axis oriented vertically to block the light reflected by the water surface. Note that if the fisherman moves his head up or down (nodding) the line joining the temples remains horizontal and the sunglasses continue to block the glare (of course, if he leans his head to one side the filters start to point in the wrong direction). By the way, they are not only used by fishermen but in all other water-sports. They are also becoming popular with truck drivers and for general outdoor activities. The last five years have seen a jump in their sales and are the fastest growing segment in eyewear.

Frequently asked questions about polarized sunglasses

How do I know if mine are polarized?
Very easily done. Just look through the glasses at the reflection of any object on a window panel (but not at yourself! you have to look at an angle to the glass). Then, turn the sunglasses around as if they were the hands of a clock facing you. If the intensity of the reflection doesn't change with respect to what you see through the window, they are not polarized.

I still don't understand, why are polarized sunglasses better than normal dark sunglasses?
Normal sunglasses decrease the intensity of everything by the same amount. Polarized sunglasses can selectively eliminate the reflection from light coming from above the water surface.

Then, could polarized glasses be crystal clear?
Nope, they will always decrease the intensity of unpolarized light by at least half. In practice somewhat more because of losses in the material. They come in all shades from light gray (only polarizing) to very dark (polarizing plus black tint), and also light sensitive (photochromatic). You can even find sunglasses with darkness adjustable by the user.

Do polarized sunglasses help see fish and rocks below the water surface?
Yes. First, if there is glare, they help a lot by reducing its blinding effect. Second, even without glare they selectively reduce other reflections from objects above water, including clouds and even the sky (the reflected sky gives most of its blue color to the sea). Finally, light coming from under water is slightly polarized in the vertical plane (polarized on transmission). The end effect is that the water seems darker but more transparent! But remember, it only works if you look at the water at some angle and not straight down.

Does it matter the time of the day?
Yes. Maximum polarization is obtained when the sun is at about 37 degrees from the horizon (in theory 100% polarization at the Brewster angle). If the sun is very low or very high the sunglasses will be of little help in filtering the glare in calm seas. A rule of thumb would be that polarized filters limit the glare from calm waters for a sun altitude between 30 and 60 degrees (but see next question). Anyway, it should be stressed that polarization won't help in looking directly at the sun (except in decreasing the overall intensity of everything by half).

Does it matter the choppiness of the sea?
Yes. When the sea is ruffled the sun reflection becomes the familiar glitter, an elongated pattern of shimmering water stretching towards the sun. Because different parts of the glitter are reflected from different wave slopes, the degree of polarization varies from place to place. In those conditions the sunglasses will also help for high or low suns and the benefit will depend on where you are looking. As a side note, the width and length of the glitter together with the altitude of the sun can be used to compute the height of the waves without ever getting close to them!

Can polarized sunglasses help when driving a car?
Yes. Those pesky bright reflections of the sun on the cars ahead can sometimes be attenuated a good deal. They tend to be horizontally polarized, thus perfect for vertically polarized sunglasses. The reason is that the surfaces that you see on the car in front of you (the back window, the trunk door, and even the roof) will be slanted towards you, while the sun will be more or less aligned in the vertical plane through both cars (if not you wouldn't see its reflection from those surfaces). However, if the sun is relatively low behind you, the sun rays will be near perpendicular to the reflecting (vertical) surfaces which won't polarize the light. The sunglasses will help more with the reflections from the glass than from the metal as the former are polarized to a higher degree. What about the brightness of the road itself? That light is also partially polarized, but by scattering (as opposed to reflection). The direction of polarization will change with the direction of the road with respect to the position of the sun. The rule is that the polarization is tangential to a circle centered on the sun. That means that if the sun is in front, behind, or high above, the road brightness will tend to be horizontally polarized and the filter of the sunglasses will provide some help. However, if the sun is to one side, the polarization will rotate vertically, the more so the lower the sun happens to be. Of course, if the road is wet you get the same anti-glare power than at sea.

Can polarized sunglasses help in skiing and other non-water sports?
Sometimes yes, sometimes no. The snow glare is not polarized, so they won't provide extra help in that regard (although often advertised for that purpose). But, with the sun high, the air-light (haze + sky) near the horizon is polarized by scattering and the polarized sunglasses can make features far away really stand out (this is used in fire detection). On the other hand, with the sun low the sunglasses could be detrimental looking south or north, as the air-light would be vertically polarized. Other situations can be thought were they would be useful, but remember that one reason they are so good in water sports is that the reflector always remains horizontal!
· Sunglasses Shop has a collection of Polarised Sunglasses for under Ј20.
· Also visit our Polarised pages for the full range of polarised eyewear
Polarized lenses
Oakley Woman Sunglasses
Oakley Ladies Sunglasses Collection
Prada Sunglasses Collection

The Oakley ladies sunglasses collection is set to grow from strength to strength and is comparable with not only the top ladies designer models but the top ladies sports models too.

If you are investing in one pair of ladies sunglasses this year, make it a pair of Oakley Woman Sunglasses and you will not go wrong.

The benefits of Oakley Woman sunglasses compared to many other brands are numerous, the best lenses in the world featuring Oakley HDO lenses as well as styling that is comparable with the market leaders.

All Oakley Woman sunglasses come with a free case, to ensure your purchase remains protected when not on your head (although these moments will be rare!)
Oakley Woman Sunglasses

Shoreham Rowing Club
Sunglasses Shop has donated some gifts to be raffled at the Shoreham Rowing Club 10K row in Brighton for Chestnut Tree House.
Chestnut Tree House is for terminally ill children and their families to try to make this time left together as pleasant as possible.
Those who wish to support the event please contact the rowing club.
"The mad people of Shoreham Rowing Club are doing a sponsored 10km row and 10km run for Chestnut Tree House which is the only children's hospice in Sussex.
The row is taking place on the Adur river if the conditions are windy, or if it is calm enough then it will take place out at sea. Three sets of coxed fours have already completed the 10 km row on the river, the rest will complete the row this weekend. A small group of these rowers are then going on to do the run organised by the hospice on the 3rd September in Littlhemapton. Shoreham are holding a raffle to fundraise for the event and the lovely people at www.sunglasses-shop.co.uk have kindly donated us some fab prizes to help with our fundraising efforts. Pictures will follow..."
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вторник, 16 октября 2007 г.

Why wear sunglasses

A comparison of the findings for 2000 and 2002 shows that there is relatively little change although some apparent diminution in the importance attached to some key factors including UV protection. However, this seeming decline over time results from research for 2002 finding a slightly higher proportion of non-buyers within its sample - this difference is not large enough in itself to be a significant shift.

When looking at the results for attributes in order of their importance, it is apparent that consumers are concerned to achieve adequate protection from UV rays, which implies that there exists high consumer awareness of potential eye damage from this source. The functional aspect of sunglasses is also underlined by the importance attributed to choosing those which are suitable for driving, and sunglasses that reduce glare. Glare is usually considered particularly relevant for consumers spending time surrounded by snow or water (perhaps sailing or angling for instance), but it also affects those in urban settings surrounded by glass.

The same awareness does not extend to blue light, however, which can also cause long-term damage to the retina. This particular risk to eye health has not been as commonly referred to in the media as has the potential damage from UV radiation and this undoubtedly accounts for the implied lower response rate with regards to blue light.

Within the context of safety, 22% of respondents are likely to specify sunglasses which meet the 1997 BS EN standard and carry the CE mark. Although this is a relatively substantial proportion of respondents, the fact that this attribute is not more widely noted suggests that compliance may very well be assumed by some buyers. It is also notable that as many as 21% of all respondents indicate that they select prescription sunglasses (in comparison with 60% of adults who wear spectacles). Prescription sunglasses are outside the Mintel definition, but this finding underlines their importance to total sales.

Across the sample as a whole, the functional aspects of sunglasses, particularly UV protection, take precedence over attributes such as fashionability or branding, although this is not to underplay the importance of the latter. Furthermore, with the sole exception of the all-important aspect of UV protection, there are very significant variations by age group

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пятница, 21 сентября 2007 г.

Opticians and specialists

Opticians vary in their stocking policy for non-prescription sunglasses. The majority, including some of the largest such as Dollond & Aitchison , continue to only sell prescription lens sunglasses. By contrast, certain other multiples, such as Vision Express and David Clulow , offer extensive ranges of premium brands, while other smaller multiples and independents such as Collison vary in their approach, perhaps stocking just a small number of premium brands, occasionally supplemented by less expensive models. Black & Lizars , the small Scottish multiple, specialises in sports sunglasses alongside its expertise in spectacles for sport. In addition to its own outlets, the upmarket optician David Clulow has in-store outlets for sunglasses at Selfridges and Harrods , in addition to a specialist sports sunglasses department at the latter. This retail category also includes a small number of upmarket independents selling their own designs in eyewear including the French Alain Mikli (also available in selected David Clulow outlets), Cutler and Gross and Kirk Originals .

Since those opticians that do sell non-prescription sunglasses usually specialise in more upmarket brands, their average retail price will considerably exceed that across the total market (and the same will also be true of most prescription sunglasses). They have therefore benefited from the broader trends which have favoured the premium brands, and the retail sector as a whole could benefit from greater involvement in this market.

The Sunglass Hut-Watch Station group has also boosted this retail category. The company has 55 outlets and was instrumental in introducing newer US fashion names in particular. More importantly, its introduction has widened the availability of upmarket brands in general, so maximising potential sales. More specifically, the company has done much to bring upmarket fashion brands to the attention of younger buyers in the high street and shopping mall, especially younger men given its bias towards sports brands such as Maui Jim , Arnette and Killer Loop , as well as others such as Ray Ban . Outlets have also smoothed their sales curve through the year by running most in combination with Watch Stations, and the fact that it is now part of Luxottica will give it assured backing for any future developments.
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среда, 5 сентября 2007 г.

Sunglasses Fashion

Sunglasses may be seen as ever more firmly embedded as part of the accessories sector. This means that not only do haute couture and increasingly numerous other fashion designers include them as part of their product range, as has long been the case, but the market includes an ever more diverse range of accessory or clothing specialists now including sunglasses within their portfolio. That said, such brands do not necessarily sell large volumes and their distribution is often limited. Examples range from the sports-oriented such as Reebok , Nike and adidas , to young accessory brands such as Guess and Diesel , more mainstream accessory companies - Kenneth Cole or Anne Klein - and retailers themselves from the largest - Marks & Spencer - to smaller operators such as the jewellers Agatha . It is not surprising that Oakley - as one of the more successful 'younger' sunglasses companies - should have developed an extensive complementary range of clothing and other accessories which could be expected to sell well to its established customer base. Fashion also performs another role. While it may be argued that it is the high-fashion names that are leading the way, at virtually all price points there has been an acceleration in the pace of change with fashion now playing such a vital part. This both meets consumer demand for a fashionable and stylish product, and stimulates further demand in itself so both forces of supply and demand are working together to reinforce growth, especially at higher price points. Although more classical shapes and finishes are always available, more radical shifts are now introduced each year making (for the most fashion-alert buyer) pre-existing sunglasses more rapidly outdated. This factor has made a significant contribution to promoting unit sales over time within all parts of the total market, as well as accelerating the product purchase cycle. This development is particularly relevant to high-fashion names since this would be intensified by the fact that their typical customer is likely to be far more fashion-aware than average and prepared to pay more and buy more frequently.

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