[url=http://www.evergrow-optical.com/single-vision-lens/]Prescription lenses[/url] are the heart of what makes a pair of glasses provide the sharp, clear vision you want to have. There are several types of prescription eyeglasses to address your visual needs, whether you are nearsighted, farsighted or need multiple prescriptions in one lens:
Single Vision – Single vision prescription lenses are used to correct a single vision problem such as nearsightedness, farsightedness, astigmatism. They contain the same amount of vision correction throughout the entire lens. In terms of single vision reading glasses, full frame readers are the most common. You’ll also find single vision lenses in half frame reading glasses which are narrower and sit at the end of your nose for easier up-close and distance viewing.
Multifocal Lenses – People who have more than one vision problem often need eyeglasses with multifocal lenses. Multifocal lenses, such as bifocals and progressive lenses, contain two or more vision-correcting prescriptions.
Bifocal – Bifocals contain two prescriptions within the same lens. The eyeglass lens is split into two sections; the upper part is for distance vision and the lower part for near vision. When you’re looking at someone who is wearing bifocals, you can often see the line between their nearsighted and farsighted prescription.
Progressive – Progressives are multifocal lenses that contain three main fields of vision including near, intermediate and distance. However, progressives do not have a visible line between prescriptions. This gives the wearer a seamless and uninterrupted transition when looking from up-close objects to far-away distance.
Computer Glasses – The lenses of computer glasses are designed to deal with eyestrain caused by computer screens. Computer glasses help with an intermediate distance of around 20 to 26 inches, which is the distance most people sit from their monitor. Many computer glasses have tinted lenses to block out blue light radiating from your electronic devices.
Reading – Even if you don’t have an eyeglass prescription from your eye doctor, you may find yourself needing reading glasses. A valid prescription is not required to purchase reading glasses, though your eye doctor can tell you the magnification you need.
Which Is Better Bifocal or Progressive Lenses?
When you are now thinking about which lenses you should choose. Stay with me because we will break down exactly the pros & cons of progressives and [url=http://www.evergrow-optical.com/bifocal-progressive-lens/]bifocals [/url]for you.
In most cases, progressives are a better choice. Because they provide a continuous clear vision from far to near and in between. Although you need to plan in a little more time to get used to them due to the blurry sides. Progressives also look better because of the missing line. And if you need a strong reading zone they will not have a blurry gap in front of you. But you will learn in the article when each of them would work better.
Usually, bifocals have a bigger reading segment. However, this depends on what kind of segment you choose in your bifocal lenses. There is a variety of them. You can choose between different shapes of the reading segment and different sizes. The standard bifocals come with a shape that has a flat or slightly rounded top and has a semicircle shape in the bottom. The size of it varies between 25-28mm which gives you as a wearer the ability to perform really big eye movements as you read your newspaper.
But bifocals just provide you with only one sharp distance. Compared to bifocals, progressive lenses have a smaller reading zone that gives lets you see two to three articles clearly in your newspaper depending on your prescription. But progressive lenses enable you to have every distance sharp between the distance vision and the near range which bifocals do not. In progressive lenses, you can not really choose the size of the reading zone but you can stretch the transition into the reading zone a bit more to get more out of the middle distance.
On the one hand, really short progressive glasses will have a smaller zone for the middle distance like your laptop and you do not have to look down as much while reading. On the other hand, you get really long progressive lenses to force perform bigger eye movements down to be able to read. But therefore you get a slightly bigger reading zone.
Blue Light: the good and the bad
The [url=http://www.evergrow-optical.com/blue-cut-lens/]light[/url] that reaches and enters the human eye is divided into visible light, comprising wavelengths from 380 to 780 nm, and non-visible light, which includes light in the ultraviolet range (UV light) and the infrared range (IR light).
Experts have been aware for some time that UV light can potentially damage biological tissue, such as our skin and eyes. That is why people typically take precautions to protect themselves from the sun, using items such as sun cream or a pair of sunglasses. However, visible blue-violet light also has the potential to cause damage to our eyes. Although blue-violet light has less energy than ultraviolet light, it is almost entirely unfiltered as it passes through the eye and reaches the retina. By way of contrast, ultraviolet light is almost entirely absorbed by the front part of the eye, and significantly less than 5% of it reaches as far as the retina.
The blue component of light between 380 and 500 nm is also known as high-energy visible (HEV) light. In particular blue-violet wavelengths between 380 and 440 nm are seen as potentially damaging and have been implicated as one of the possible causes of photoretinitis, i.e. damage to the retina caused by high-energy incident light.
Light does more than just help us see, it is also an important means of regulating our biological rhythms and affects our general well-being. Light influences whether or not we are awake, focused and productive and feel energized and healthy.
Scientific studies have confirmed the biological effect of light on our body. Ultraviolet light, for example, influences the production of vitamins. Exposure to bright light and, in particular, the portion of blue light affects our hormonal balance. Hormones in the body regulate how a person feels as well as their sleep-wake cycle. In daylight, the portion of blue light is relatively high, whereas it is significantly reduced in the evening.
When it's bright outside, the body releases serotonin – also known as one of the "happy hormones" – and cortisol, a stress hormone. Both of these make us feel awake and active. However, melatonin is considered a sleep hormone and causes us to feel tired and sleep soundly when it is dark.
Light, in particular blue light that reaches the retina, also affects our psychological well-being. That is why light therapy is successfully employed to treat winter depression and insomnia. But, as is so often the case, the axiom "everything in moderation" still applies. Exposure to too much light also carries certain risks and can even be damaging.
What Are Photochromic lenses?
[url=http://www.evergrow-optical.com/photochromic-lens/]Photochromic lenses[/url] are just like normal lenses but they automatically become dark when we move in the sunlight. Ultraviolet rays coming from the sun affect the molecules present in the photochromic lenses therefore, these lenses change their colors. These lenses get darker in bright lights and vice-versa.
These lenses, therefore, provide the best vision in all lighting conditions. Transition is the best and very well-known brand of photochromic lenses therefore, these lenses are also known as “transition lenses”. The other names also which have been given to these lenses are:
Auto tinted lens
Variable tint lens
Photochromic lenses and polarized lenses i.e. sunglasses are very different from each other as the sunglasses have a set tint that protects our eyes from glares but they are not changeable whereas the photochromic lenses easily adapt to the nature of the light present around and changes accordingly.
Helps in reducing eye strain and eye damage by blocking up to 100% harmful UVA/ UVB light.
These glasses are very convenient to carry as you do not need different glasses for different lighting conditions.
These lenses also protect our eyes from the high risk of cataracts by blocking out as much light as possible.
Photochromic lenses are cost-effective. It has the feature of both the lenses (normal lens and sunglasses).
These lenses are available in different shades, tints, and styles suitable for your taste.
Photochromic lenses get darken when coming in contact with the sunlight, blocking your windshields. Therefore, they are risky to wear while driving.
These lenses are also affected by the weather. This means that it takes more time to get dark in the winters.
Some photochromic lenses are not polarized, leading to harsh glares of sunlight. Therefore, make sure you ask the doctor about all the details of the glasses that you wear.
Sunglasses Lens Tints: Which Colour is Right for You?
It’s common for people to pick a lens colour for their [url=http://www.evergrow-optical.com/]sunglasses[/url] purely for the look. But did you know that there is a purpose to each different lens colour? Different sunglasses lens tints will perform at their best during different activities and in different environments. In fact, lens tint can boost depth perception, reduce eye fatigue, and improve vision in a wide range of weather conditions.
So, before you pick your next pair of sunglasses, it’s worth knowing a thing or two about sunglasses lens tints. Matching a tint to your lifestyle will lead to better performance from your sunglasses.
Grey lenses are one of the most popular tints. They provide good protection from glare, whether shining from above or from wet roads. Grey tints will provide plenty of protection, whilst offering the purest colour perception of all the lenses. With good performance on sunny and cloudy days, grey is a great all-purpose tint.
Brown tints perform most strongly in the sunniest weather. A brown tint will heighten contrast in sunny conditions, allowing you to clearly pick things out from the landscape. This goes hand in hand with improved depth perception over other tints, making them great for any job involving judging distance. However, this tint isn’t recommended for a cloudy, dull day.
Yellow lenses are popular with all kinds of sports people. In foggy, hazy, or low-light conditions yellow tints can provide a strong boost to clarity. This is perfect for sportsmen who need to track moving objects in this kind of weather. But that’s not all, yellow tints can also reduce eye strain from screens. So whether you’re playing cricket or playing a flight simulator, you might want to consider yellow.
Blue lenses offer practical protection from UV rays. At the same time, they’re a fashionable colour which is popular at pool-sides everywhere. A blue tint keeps colour perception strong, whilst also helping you pick out outlines. This makes them good for foggy or snowy conditions. Whether you’re hitting ski slopes or sand dunes, blue lenses will look the part.
Pink & Red Lenses
Pink or red tints bring a bold splash of colour to your look, whilst also boosting your vision. An increased depth of field makes these tints popular with both drivers and winter sports fans. By blocking blue light, this rosy tint also reduces eye strain from computers and helps the eyes grapple with changing contrast.
Green lenses are something of an underdog, offering all-purpose performance in sunny and low light environments. A green tint will greatly reduce glare, whilst keeping colour accuracy. For outdoor use in all kinds of weathers, you can’t top the adaptability of green lenses.
Sunglasses designed to last from Focus on Broadway
Picking the right tint is an important part of putting together the perfect pair of sunglasses. Whether you’re after prescription sunglasses, or looking to treat yourself to some designer frames, Focus on Broadway can help you pick from an amazing range of frames and lenses. To find your next pair of prescription sunglasses, pop in store today.