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Recently customers are paying more attention on the thickness of different lenses such as bifocal and progressive lenses. In order to better serve our dear customers, our customer service center has collected an exclusive handbook on ABBE Glasses.

Why should we know this knowledge about lens? Because of three reasons: 1. It is up to the frame you choose. For example, some semi-rim rim and large frame are not suitable for thick lens. The frame with full rims can protect and fix your lens maximally. 2. It depends on your prescription. If you have high or strong prescription, high index lens will be your best choice. The higher index lens you select, the thinner lens you get. High index lens means that the lens is lighter than ordinary index lens. No matter you have presbyopia or myopia, small frame can meet all lenses.

Remember except some special situations, usually we purchase reading glasses according to edge thickness and spectacles for myopia based on central thickness.

Here are some examples about thickness of our lenses according to the benchmark of all raw lenses’ thickness is the 65mm diameter.

• Lens central thickness standard of myopia–Single vision. The thickness of myopia eyesight below -2.25 is almost completely the same for 1.50, 1.57and 1.60 lens index. As for high index 1.67 and 1.74, the higher your prescription is, the thinner your lens thickness should be.

Thickness unit: mm

• Lens central thickness standard of myopia–Bifocal Lens.

Thickness unit: mm

• Lens central thickness standard of myopia–Progressive Lens.

Thickness unit: mm

Next, the lens thickness standard of reading glasses comes out. Usually the theory of reading glasses is the convex lens and the theory of myopia is the concave lens.

1. Lens edge thickness standard of reading glasses–Single vision.

Thickness unit: mm

2. Lens edge thickness standard of reading glasses–Bifocal lens.

Thickness unit: mm

3. Lens edge thickness standard of reading glasses–Progressive lens.

Thickness unit: mm

All statistics may exist some very little error of 0.2mm. If you want to add polarized and transition effect on your lens, it may be thicker of 0.2mm. Please note, if you want to get specific data of your lens, do not hesitate to consult us and we are waiting for you.

Always confused about how to choose best lenses for yourself? Basically, lenses include three types: single vision, bifocal and progressive lenses. So, what are they? How to select the lenses which are most suitable for yourself? And what are benefits of these lenses bringing to you? No worry, we have already prepared this handbook for you!

1.Single vision lenses

Single Vision lenses are the standard eyeglass prescription. These glasses are for one field of vision across the entire lens. Depending on what your doctor prescribed, single vision lenses help you see at one of the following distances: 1) Close, as if you are looking at your cell phone or books. 2) In the distance, as if you are looking at street signs. Single vision lenses are the most commonly prescribed lenses as they can correct your nearsightedness (myopia), farsightedness (hyperopia) and astigmatism. Single vision lenses with refractive index of 1.50 and 1.57 are free in our shop now!

Curious if you could benefit from single vision lenses? What are you waiting for? Make sure to schedule an appointment with your local eye care professional today. Singe vision reading glasses can also help correct presbyopia. Here are detailed examples:

• Near

Near lenses have prescriptions starting with a plus (+) sign and are designed for those who have trouble focusing their eyes while reading. These lenses are designed to help correct farsightedness caused by hyperopia or presbyopia.

• Distant

If your prescription has a negative (-) number and 0 ADD, this means that you need “Distance” lenses. Distance lenses are needed when things up close appear clear, while things further away look blurry. This is called nearsightedness, or myopia.

2.Bifocal lenses

Bifocals lenses include two fields of vision separated by a line. Usually the top is designated for distance vision or computer-distance vision, and the bottom for near-vision work such as reading.

It may take first-time bifocal wearers some time to adjust to the lenses. This is largely due to learning how to move your eyes between the distance and reading portions of the lens. The best thing to do to get used to your bifocals is to wear them as much as possible.

3.Progressive lenses

Progressive lenses include three fields of vision, without lines. The top portion is used for distance-vision, the middle portion (corridor) for mid-range vision, and the bottom portion for the near-vision or reading.

Progressive lenses include three fields of vision, without lines. The top portion is used for distance-vision, the middle portion (corridor) for mid-range vision, and the bottom portion for the near-vision or reading. Unlike bifocal lenses, progressive lenses have no line and are optimized for not only reading and distance, but also for a third intermediate distance, such as your computer screen. The process of adapting to a new prescription and lens can take anywhere from a few days to one full month-even if you have previously worn progressive lenses. Try to not go back and forth with your old prescription. Wear your new glasses at home and at the office to start, then driving as soon as you are comfortable with your new glasses.

Do you see the two areas here on the progressive lens named peripheral distortion? Remember do not always move your eyes from left to right, this would cause qualm.

Honestly, compared with frames, what you should care for more is lens. Lenses are made from optical materials like resin, glass, PC etc.

　 1. Resin material

What is the resin? Do you know the benefits of this material that is used in making lenses? Or some shortcomings?

Resin is a hydrocarbon (hydrocarbon)-derived secretion originating from plants, especially conifers, which is valued by professionals for other special chemical structures. Resin can be divided into natural resin and synthetic resin. Resin lenses, also named plastic lenses in the market, chemically synthesized from natural resin, then are processed and polished with precision instruments.

Obvious advantages of resin lenses include: first, it is light-weight and more comfortable to wear. Secondly, the resin lens is safe because of strong impact resistance and is not easy to break. (If by any chance the lens is crushed, the fragment is not only small, but also less sharp. The injuries of eyeball and face can be minimized. This is the main reason why the lens is called “safety lens” on the market.) Thirdly, the resin lens can almost completely block ultraviolet rays with a wavelength of 350mm or less, and the effect is much better than that of glass lenses. Fourth, resin lens also has good rate of light transmission up to 92% which is higher than glass. Fifth, the resin lens can be easily reworked to meet special demands such as adding different coatings and dyeing. (Resin lenses are apt to dye and match with clothing and fashion.) Sixth, with the innovation and improvement of the coating technics, the resin lens has become the mainstream of the lens on the market relying on good wear-resistance. Seventh, due to the lower thermal conductivity of the resin lens, it has strong anti-fog function which is not easy to be blurred by steam and even if it is blurred, it will quickly disappear.

Furthermore, Resin lenses also have other benefits. Here are extra three points: 1. generally, high-heat and small-volume substances tend to cause dents and spots on the glass, but if they touch the resin lens, they will automatically bounce off and will not cause any marks on the surface of the lens. 2. The surface reflection of the resin lens is lower than that of the ordinary glass lens, and it is also less glaring. 3. Resin lenses are extremely resistant to chemicals and solvents. Almost all household solvents and chemicals cannot damage them.

Some disadvantages of resin lenses:

• Easy to scratch: the scratch resistance of resin lenses is inferior to that of glass lenses. Although it can be improved by hardening surface, the effect is limited.
• Thicker than glass lenses: with thick lenses, it is a nightmare for people who want beauty and fashion, especially for people having deep myopia. Although it has been greatly improved in recent years, it is still much thicker than glass lenses.
• Easy to deform: due to the low density of the resin lens, it is likely that the deformation happens when framing.
• Non-resistance to high temperature: though the resin lens is a thermosetting material, the lens surface of multi-coatings may be cracked for high temperature.

       2. Glass material

Every time you buy eyeglasses at local shops, you will be asked what kind of lenses do you like? Glass lenses or resin lenses or something else? Have you met such questions? Frankly, I have been always asked which one is better. Then I was persuaded to buy that eyeglasses the seller recommended. Sometimes, our customers should know something about glasses, in the case of they being cheated or lied to. We need to learn something about glasses to show that we are smart customers and would not be easily dealt with such perfunctory treat. Let us be the customers who know the ropes!

What is the glass lens? The main raw material of glass lens is the optical glass, which has superior optical attributes owning good light and stable refractive index. Secondly, glass lens has high refractive index and the highest refractive index is 1.90. Finally, the surface of glass lens is very hard and more wear-resistant.

However, the glass lens is heavy in virtue of material reasons, which feels uncomfortable to some extent when worn. The glass lens can only be dyed by several colors and it is not cost-efficient. With fragility of the glass lens and improvement of making and processing the resin lens, the use of glass lens is fewer than before.

       3.Polycarbonate material

PC lens, also known as polycarbonate, is tough and not easy to break, which can effectively prevent lens cracking during intense exercise. Because PC lens is light-weight and has good UV protection, especially for resisting compression and shock. It is widely applied in sport glasses and children glasses. However, owing to high price and complex process, PC lenses are only sold in small quantities at the market.

Therefore, please do remember your lenses should be tough, quality and comfortable to wear. Nothing is perfect! You need to listen to suggestions from opticians and choose the most suitable lenses for yourself according to your needs. Sometimes the expensive lenses do not mean the best lenses for you! And it is also a very important tip for you to notice when buying glasses online.

They are lenses that changes color when it comes into contact with light/UV. Transitions is actually a brand name, the name for such lenses are actually called photochromic lenses. Photo- meaning light, -chromic meaning color.  They typically come in 2 colors: grey and brown.

Grey and brown are the common tints for sunglasses as they cut out glare without altering much color of nature, so what you see with the tinted lenses is what you get (minus the annoying glare, of course!)

Transition lenses are basically lenses that have special coating that when interacted with UV rays, would darken the lens and reduce the amount of light/UV entering the eye.

If you go to places with high UV index, i.e. top of the mountain and/or somewhere in the North/South Pole, you will realize that these lenses do an excellent job in transiting your normal pair of prescription lenses into a pair of prescription sunglasses. Talk about being convenient and not having to take off your prescription glasses and pop on your sunglasses! Or wearing contacts just so you can wear your sunglasses because it did not have prescription!

However, as this is a type of coating, it can cause the lenses to yellow quite easily. And it is especially so if the glasses has been out there interacting with the UV rays a lot.

One thing you have to remember is that not all transitions lenses are the same. Some darken in a car and some do not. This is partially because “regular” transitions lenses use UV light to darken the lens. Modern windshields have an anti-UV coating so these lenses will not darken in that situation.

In addition, when entering indoors from outdoors, these lenses do take some time to go back to being clear, so your glasses would look kind of weird for the first 30–40 seconds when you walk through a door from outdoors! https://www.abbeglasses.com/ There are good quality lenses available for you here.