Posts Tagged ‘photochromic sunglasses’

Photochromic sunglasses

July 6th, 2015

Photochromic sunglasses are equipped with photochromic lenses, which darken substantially in response to UV light in less than one minute and then continue to darken very slightly over the next fifteen minutes. The lenses will begin to clear as soon as they are away from UV light, and will be noticeably lighter within two minutes and mostly clear within five minutes. However, it normally takes more than fifteen minutes for the lenses to completely fade to their non-exposed state. The best quality photochromic lenses can offer very quick transition times.

Sunglasses or prescription eyeglasses that darken when exposed to the sun were first developed by Corning in the late 1960s and popularized by Transitions in the 1990s. In fact, because of the extreme popularity of the Transitions brand, these lenses are usually referred to as transition lenses. The correct term for these glasses is photochromic or photochromatic, which refers to a specific chemical reaction the lenses have to ultraviolet (UV) radiation.

Photochromic lenses have millions of molecules of substances such as silver chloride or silver halide embedded in them. The molecules are transparent to visible light in the absence of UV light, which is normal for artificial lighting. But when exposed to UV rays, as in direct sunlight, the molecules undergo a chemical process that causes them to change shape. The new molecular structure absorbs portions of the visible light, causing the lenses to darken. The number of molecules that change shape varies with the intensity of the UV rays. When you go indoors and out of the UV light, a different chemical reaction takes place. The absence of the UV radiation causes the molecules to snap back to their original shape, resulting in the loss of their light absorbing properties. In both directions, the entire process happens very rapidly. An important note about photochromic lenses: because they react to UV light and not to visible light, there are circumstances under which the darkening will not occur. A perfect example of this is in your car. Because the windshield blocks out most UV light, photochromic lenses will not darken. For this reason, most sunglasses with photochromic lenses also have a certain amount of tint already applied to them.

The Combat of Merits VS Demerit of Photochromic Sunglasses

March 15th, 2012

Photochromic sunglasses? What might that be? Do they ring a bell to you? If not, you shall really brush up on your knowledge about sunglasses in order to catch up with the latest fashion. Photochromic sunglasses, also known as transitional sunglasses, have been enjoying a skyrocketing popularity among glasses wearers for so long that you might rack your brain wondering how they do the trick to endear themselves to so many people. This article serves an explanatory note of photochromic sunglasses to highlight their merits and point out their shortcomings, just for your information.

What are photochromic sunglasses?

Photochromic sunglasses are sunglasses having lenses that darken on exposure to UV radiation. Once the UV is removed (for example by walking indoors), the lenses will gradually return to their clear or transparent state. To put it simply, on a bright and sunny day, these transitional lenses adjust automatically to the intensity of light and hence, control the amount of light that falls on your eyes. UV rays are blocked 100% just like it would with a pair of sunglasses, which means you do not have to carry a pair of extra sunglasses when moving outdoors.

What are the merits of photochromic sunglasses?

Photochromic sunglasses are a veritable boon for those stuck with corrective eyewear. With the aid of photochromic sunglasses, they can save their budget to enjoy the same pleasure of stylish cool image and all-round protection imparted by sunglasses, instead of buying prescription sunglasses in addition to transparent corrective glasses. Those without 20/20 vision stand to benefit in plenty from these transitional sunglasses both financially and physically. This is really reassuring for people with vision loss, for they don’t have to cover their corrective eyewear with those bulky and cumbersome sunglasses, which for sure pose an extra burden to wearers and also mar the facial beauty of yours. Their lenses can be made of glass, polycarbonate or another plastic. So the price of photochromic sunglasses is not too intimidating for you to set your hands on one pair.Since they adjust automatically to improve contrast and protect your eyes against glare, they are great for reducing eye fatigue and strain. Besides, the time required for them to get dark according to the intensity of light and to get clear does not exceed 30 seconds. Furthermore, photochromic lenses come in all kinds of materials and designs and gray and brown tints making them cool and chic as well.

What are the demerit of photochromic sunglasses?

Many photochromic lenses do not work through car glass, so they aren’t an effective option for the changing light conditions present while driving. If you need photochromic lenses for driving, shop for a pair that is designed for driving use. If you’re looking for a pair of glasses for more reliable, steady light conditions, as in lying out on the beach, you’d be better off with a pair of dark lenses as opposed to a photochromic pair.

Such being the case, the promising merits greatly outweigh the demerit, ensuring that photochromic sunglasses are a dependable and trustworthy alternative to the combination of sunglasses and prescription eyeglasses. Whenever and wherever, as long as you have photochromic sunglasses on your side, you are in a position to enjoy a safe and sound vision to the utmost. Firmoo happens to have in store a wide range of great quality and low-priced photochromic sunglasses. The cheap glasses are close at hand, so why don’t you give it a shot? The return and refund policy is quite convincing and alluring. Go ahead and have a go at it!

Photochromic Sunglasses: The Best Buy You Could Ever Get For Your Money

October 17th, 2011

Are you still spending loads of money on multiple pairs of glasses and shades just to keep up with your frequently-in-and-out-of-doors life style? If yes, the next time you invest on a pair of glasses, try photochromic sunglasses. These unique shades keep transparent when you are indoors and darken immediately as soon as you step outside your house. One pair of such sunglasses will surely prove to be the best buy you will ever get for your hard earned money.

Photochromic Sunglasses

Some may say with all the new features and technology, a pair of photochromic sunglasses must cost way more than regular sunglasses. Well, if you do your math that way, I have to say I hear what you are saying, but you are completely wrong. The fact of the matter here is by purchasing a pair of photochromic sunglasses, you actually save yourself a huge amount of money that you would otherwise have to spend on a whole set including a pair of eyeglasses, a pair of sunglasses, and sometimes even a pair of reading glasses. With photochromic sunglasses, you will not only no longer have to juggle different pairs of glasses constantly, but also save yourself a fortune for since there aren’t that many pairs for you to keep up with, you are less likely to mix things up and drop or break them. Just one pair of all-in-one shades needs to be taken cared of, thus it will undoubtedly last much longer.

Photochromic Sunglasses

Despite the many merits, there do exist a drawback that’s probably going to make photochromic sunglasses look not much of worthy buy. And that is the fact these shades won’t darken when you are driving a car, which just might as well be the occasion when you need the darkening the most. Due to such downside, it is advised that drivers put on an extra pair of UV shades when they are wearing photochromic sunglasses even if they are driving in the sunlight. Some may say such requirements add to the cost. However, a pair of cheap UV shades can still compare to the eyeglasses or reading glasses you otherwise have to pay for. Plus, besides when you are behind the wheel, photochromic sunglasses will do all the things for you, thus they are still a pair of worthy buy in spite of this little dissatisfaction.

From the math we’ve done for you above, it is pretty obvious that photochromic sunglasses are a worthy buy. But, it doesn’t necessarily mean they are for everyone. So, weigh the pros and cons before you decide to purchase one pair. And, once you’ve made up your mind, just go for it.

Prescription Photochromic Sunglasses Provide You With The Ultimate Convenience

August 18th, 2011

For people who need prescription eyeglasses to help them see clearly, summer is a tough season. They have to constantly switch between their conventional prescription sunglasses, which provide them with both UV rays protection and corrective vision, and their prescription eyeglasses whenever they goes outdoors or indoors. With prescription photochromic sunglasses, they don’t have anymore. Because of the substances called silver halide or silver chloride distributed on the lenses, which would undergo a chemical reaction at the exposure to UV rays and then absorb sunlight, photochromic lenses would darken automatically when exposed to sunlight and return to a more clear state when the sunlight is away. With this feature, the wearer need not change to a pair of prescription sunglasses before they hit the road and switch back to their transparent prescription eyeglasses when they go back home. They can just put on a pair of prescription photochromic sunglasses and everything is taken cared of once and for all.
Prescription Photochromic Sunglasses

Every coin has two sides, and prescription photochromic sunglasses are no exception to that. Although they can almost be recommended for anyone at any time, there do exist one occasion when they are not suggested. And that is when you are driving in your car. As is known to all, the windshield on our car can block out most of the UV rays. However, as it turns out those UV rays are crucial in triggering the substances on the lenses into chemical reaction and subsequently causing the lenses to darken or lighten. When the UV rays are gone, the glasses won’t work as well as before. So, even when the sunlight is directly in your way, burning on your eyes, those photochromic lenses won’t darken at all.

Prescription Photochromic Sunglasses 1

Besides not suitable for driving occasions, some photochromic sunglasses may take a little time to adjust to a new light condition. For example, when you enter the room, it may take a couple of seconds for the lenses to go back clear again. Although it may be tiresome at times, it certainly is better than having to change your glasses. You just need to get used to it and before long you will forget it all. After all, it’s only a few seconds.

At the present, prescription photochromic sunglasses are mainly available in two brands: Transitions and Reactolite. The former is the leading company in this area and the later is rapidly catching up. The problem with those two is photochromic sunglasses sold by them can cost a fortune. A nice alternative to them are inexpensive photochromic sunglasses online. These glasses sold online are of the same quality as those from Transitions and Reactolite and they are priced at much lower rates. So, if you haven’t already, go online and check out some of the online stores for your pair of prescription photochromic sunglasses.

Photochromic Cycling Sunglasses: The Best Shades to Put On When You Are On The Road

August 16th, 2011

For a cyclist, whether him being a professional cyclist or just a regular biker, eye protection is always a hugely important issue, one that takes a lot of effort to address. First of all, he needs to tackle the increased airflow, the flying debris and insects. Secondly, he wants to protect his eyes from harmful UV rays and glare. And thirdly, he need to adapt to the always changing weather conditions. To address the first two problems takes no more than a normal pair of quality cycling sunglasses. To address the last one, however, is a bit more daunting. Traditionally, the problem can only be solved by constantly switching between multiple pairs of sunglasses, which is kind of a headache for a regular biker and totally impossible for a competitive racer. Now, with the advent of photochromic cycling sunglasses, everything is changed. The cyclist only needs to put on one pair of photochromic sunglasses, the adjusting to weather conditions problem can be taken care of once and for all.
Photochromic Cycling Sunglasses

For those who are not familiar with photochromic sunglasses, these sunglasses have the capacity to react to the light condition, which means the lenses can actually darken or lighten in accordance to the exposure of them to UV rays. So, when you are biking on a sunny day and the sun is out and there is UV rays everywhere, the lenses will automatically darken, providing the required protection. And when the sun are blocked by the clouds or by the shadows of a forest or maybe when you are cycling during the night, those lenses will automatically lighten back up, providing you with the perfect vision to look out for the road conditions (pit holes, wheel ruts, ice patches or in the case of mountain cycling, tree branches or roots).

Photochromic Cycling Sunglasses 1

For those cyclists who suffer from vision problems and needs corrective glasses to help them see, photochromic sunglasses lenses can also be made with prescription. Therefore, they can always find the corresponding prescription photochromic sunglasses to match their particular vision requirements.

Basic points of photochromic sunglasses

June 30th, 2010

Among all sunwear products, photochromic sunglasses are widely considered as an advanced form. It is widely known that regular sunglasses are made with fixed degrees of darkness in the lenses. In this case, dark lenses usually block more sunlight, while light ones have a weaker ability in sunlight filtration. However, sunglasses using photochromic lenses are completely different that they are adjustable in different lighting conditions. A basic point of these lenses is that they darken on exposure to ultraviolet radiation and gradually return to a clear state when the UV is removed when the wearer enters indoors. Some people may think that this is a magic capability. And what is more exciting, this ability does not rely on a special lens material. It is feasible to use glass, polycarbonate or other plastics to produce photochromic lenses. In recent years, these products have been quite popular.

The photochromic properties of these lenses are created by embedding microcrystalline silver halides or molecules in a glass substrate. While using plastic materials, manufacturers apply organic photochromic molecules to achieve the reversible darkening effect. And the UV rays contained in sunlight are the exact part that causes the lenses to darken. This basic fact explains why these lenses will not become dark with exposure to room light. Photochromic sunglasses have been widely praised due to this advanced functionality. In most cases, they use prescription lenses so that such a pair will function as regular Rx glasses when staying indoors. This greatly eliminates the need to change separate pairs of glasses and sunglasses when it is necessary to make switches between indoor and outdoor environments.

A disappointing fact may be that these sunglasses are imperfect. Photochromic sun glasses made by different corporations usually take a little bit longer to clear than to darken. In an extreme case, it may take up to an hour for these lenses to clear. During this transition time, normal, clear vision will be affected. Another drawback of photochromic sunglasses is that they also react to temperature that they darken much more in cold conditions. This indicates that these sunglasses will work less effectively in summer. It is necessary for customers who are interested to know these points.

Related pages – UV sunglasses, Polarized Bifocal Sunglasses, Progressive Sunglasses