The Eyewear Guide
- Posted on: May 18 2020
THE WEEKLY VIEW
Mountain View Eye Center’s Weekly Blog
The Eyewear Guide
A comprehensive guide to frame and lens selection.
With so many options to choose from, buying glasses can seem like an overwhelming task. In this blog, we’ll go over what your options are, what our opticians recommend, and why you should use their expertise to have the best possible eyewear buying experience.
What makes up a pair of glasses?
The technology behind a pair of glasses is surprisingly complicated. Frames are manufactured out of a variety of materials, from woods to plastics to precious metals, which are sourced from all over the world. They are assembled and polished by hand in a process that can take several days. Frames are often made up of dozens of small parts that may not even be visible when looking at the glasses, such as hinge pieces, tiny screws, or metal cores. These small details can make a big difference in the fit and function of your eyewear. You may think that once you have selected a frame you are done, but there are several more options to consider.
The true technology behind eyewear lies in the lenses. Spectacle lenses have evolved significantly since they were first introduced sometime in the 13h century. Even over the last decade there have been significant improvements in lenses, specifically in digital lens design. This type of design uses mathematical equations to grind the lenses in precise areas to give the wearer the broadest field of clear, usable vision. Additionally, there have been great advancements in lens materials, coating and tints.
There is so much to discuss when breaking down all of the parts of a pair of glasses. We’ll focus on the 5 main components:
Frames, Lenses, Lens Materials, Lens Coatings, and Tints.
As we discussed previously, there are a seemingly endless variety of frames to choose from. Glasses are not only a tool that provides clear vision, but also a way to express your own unique style. However, there is more to a pair of glasses than how they look:
First, consider how the frames fit your face. People with flatter bridges or high cheekbones will usually benefit from frames with nosepads, as these will lift the glasses off of your cheeks, and distribute the weight more evenly across your nose. Additionally, look at the size of your frames. Glasses should cover the eyes completely, but not extend over the brow, or down to the cheek. While larger frames can be very stylish, they are also heavier, and lenses that are too big actually create distortion that decreases overall clarity. Also look at the temples. Frames that are too small will cause the temples to splay at the sides, which not only looks funny, but can be painful. This also causes unnecessary stress on the frame which can lead to breakage. Temples should be long enough to bend behind the ear. If your temples are too short, they will bend before the ear, which will cause them to rub against the ear. Glasses that are too big will slide down the nose and feel like a nuisance. The best way to know if you are selecting glasses that are the right size for your face is to speak with an optician. Opticians are trained to recognize signs of poorly fitting eyewear, and they will be able to give you recommendations that meet your needs. An optician will also take into account the strength of your prescription. Choosing frames that are the right shape for your prescription will make them look, fit, and function better. For strong prescriptions, opticians will recommend glasses that are smaller and rounder in shape, to minimize thickness and distortion at the edges of your lenses.
One of the most important options to consider when buying new frames is the feel. If a pair of glasses looks great but feels terrible, you simply won’t want to wear them. When selecting new frames, consider the weight of the frame. While some people like the feel of a sturdy, heavy frame, most spectacle wearers prefer frames that are light in weight. Keep in mind that glasses will be slightly heavier with prescription lenses inserted.
Frames are usually made out of plastic, metal, or a combination of both. Material selection usually comes down to personal preference, however not all materials are created equal. Steel frames are durable, but very heavy. Some spectacle wearers may have a nickel or plastic allergy that prevents them from wearing certain frames. One of the most popular and versatile frame materials is Titanium. This material is extremely lightweight, very durable, and hypoallergenic, making it a great material for almost anyone. There are also a variety of lightweight plastic frames on the market, such as nylon and cellulose acetate. These frames may offer more options for colors and shapes than metal frames. You may have seen frames made out of more unusual materials, such as wood or buffalo horn. These materials are beautiful and unique, but have limited adjustability. Be sure to work with your optician to determine whether these glasses are a good fit for you, as there is not usually much that can be done to change the way these frames fit.
Now that you know how glasses should fit and feel, you can have fun! Glasses are the first thing that people see when looking at you, so choose frames that send a statement. Glasses come in just about any color you can think of, and the shapes are no longer limited to “square” or “round”. Think of your glasses as a fashion statement, and find a pair that let your unique sense of style show. Whether you are looking for simple and understated or bold and bright, Mountain View Optical has the frames to help you shine.
When you have your annual eye exam, your doctor will test your vision and give you a glasses prescription. They may also discuss some lens options with you. Your glasses prescription and lens options will vary based on your visual requirements, occupational requirements, age, and other ocular conditions. Your optometrist or optician will help you to determine what kind of lenses you require, but we will go over the most common lens designs here:
Single vision lenses are used for one focal length, usually either for far away or for up close. This is the type of lens that is most common for anyone under 40 years old who does not have other ocular conditions. If the doctor has determined that you require a single vision lens, your optician may recommend a digitally surfaced lens. As discussed previously, this type of lens will enhance clarity in all portions of your lens by pinpointing specific areas of the lens and grinding a compensated power into the lens. The power of a lens changes anytime you look away from the optical center of the lens, so compensation gives the wearer the clearest vision whether looking through the optical center or another portion of the lens.
If you spend a lot of time working on a computer, reading, or doing other “close-up” tasks, your optometrist or optician may recommend Anti-Fatigue lenses. These lenses are designed with your regular distance prescription at the top of the lens, and a small power boost at the bottom of the lens, which helps to magnify images while doing close-up work. This does some of the work that your eyes would normally do, which helps to eliminate symptoms of Digital Eye Strain. These symptoms include headaches, tired or burning eyes, and blurry vision. Similarly, Computer Lenses will reduce eye strain associated with computer use, but they are designed for arms-length and close up work only, and cannot be worn for distance activities or driving. For more information about Digital Eye Strain, read our blog Blue Light and Your Eyes.
If you are over 40 years of age, your doctor may recommend multi-focal lenses. This is because around age 40, the lens of the eye begins to lose elasticity, and can no longer change shape to bring close objects into focus. Multifocal lenses do just as their name implies: focus images at multiple distances. These lenses typically fall into two categories: Lined multifocals and no-line multifocals, or Progressive Lenses.
Progressive Lenses are designed to mimic your natural vision, giving you clear vision at distance, intermediate and up close. These lenses will allow you to drive, work on the computer, and read, all without having to change your glasses or reposition your frames. The convenience of progressive lenses makes them a great option for most Multifocal lens wearers, however some people will notice distortion at the edges of their lenses. This distortion, called Peripheral Blur, is present in all progressive lenses, but proper fitting of lenses and choosing the right progressive lens will help to minimize this. There are dozens of progressive lenses on the market, but the opticians at Mountain View Optical will help you select the right progressive lens for your needs.
If you cannot tolerate a progressive lens, you may want to wear a lined bifocal or trifocal. Bifocal lenses are made from 2 different lenses that are adhered together, allowing distance and near vision in one lens. Trifocal lenses are the same as bifocal lenses, but with one additional segment to allow for distance, intermediate, and near vision. Like a progressive lens, these lenses are designed to allow you to do distance and near activities without having to change your glasses, however these lenses will have a distinct line across the surface. This line can be bothersome for some wearers, as vision is impaired where the line falls, and it makes them less aesthetically appealing.
While this does not cover every lens option available, these lens designs are the most common. You should work with your optometrist or optician to determine which lenses will best suit your needs.
There are several different options when it comes to the material your lenses are made out of. Your doctor or optician may recommend a specific material based on your prescription or visual requirements.
Glass is the oldest lens material available. Lenses have been made from glass since glasses were invented. It is a very clear material that is resistant to scratches, however it is the heaviest lens material available and it is more likely to shatter and cause injury than other materials. Also, premium progressive lenses and Anti-Reflective coatings are generally not compatible with glass lenses. The benefits of these higher quality lenses and coatings usually outweigh any benefits from glass lenses.
Plastic or CR-39:
Plastic is the most common lens material. It is considered a “basic” material. Plastic is lighter than glass and very optically clear, however it is not the most impact resistant material and it is not recommended for strong prescriptions because it will be thicker and heavier than other materials. It also does not block 100% of UV rays.
Polycarbonate is most commonly used when impact resistance is necessary. It is usually a go-to material for childrens eyewear and safety eyewear. This is because it is highly impact resistant, and it blocks 1005 of UV rays. It is also thinner and lighter than both glass and plastic. But polycarbonate is not ideal when it comes to optical clarity.
Trivex is one of the newer materials on the market, first introduced in 2001. It is one of the most versatile lens materials available, as it is thinner and lighter than glass or plastic, very impact resistant, and optically clearer than polycarbonate. Trivex also blocks 100% of UV rays. It is a great choice for most prescriptions, although very strong prescriptions will benefit from thinner materials.
Hi Index plastics come in indexes from 1.60 to 1.74, with the larger number being thinner. These materials are generally indicated only for very strong prescriptions, as they are very lightweight and much thinner than plastic or glass. They also block 100% of UV rays. They have less optical clarity than other materials, and wearers are more likely to notice chromatic aberration, or colorful distortion, around the edges of their lenses.
While there are many options to choose from when it comes to lens material, it is best to discuss these options with your optician. They will be able to use your prescription to determine the best material choice for your glasses.
Coatings are the workhorse of your lenses. There are two main types of coatings, Anti-Reflective coatings, and Blue Light Blocking coatings.
These coatings are a multi-function coat applied in several layers to the surface of your lenses. They allow light to pass through the lens, rather than bouncing off of the surface. This allows the light to then enter the eye, giving you a clearer image. It also makes the lenses look better cosmetically, as this added clarity allows your eye to be seen through the lens, rather than seeing reflected light on the surface of the lens. This is beneficial at all times, but especially at night, when your eyes struggle to see images clearly due to reduced light. Additionally, these coatings include a layer of extra durable scratch protection, which helps to prevent scratches. Your lenses will also be easier to clean due to the hydrophobic and oleophobic nature of the coating.
Blue Light Blocking Coating:
A Blue Light Blocking coating has the same properties as a standard anti-reflective coating, but with the added benefit of a blue light filter. This filter helps to reduce the amount of blue light that enters the back of your eye. This light is emitted from such sources as the sun, phone and computer screens, and fluorescent lights. This type of light can interfere with our sleep cycles, and may lead to a type of retinal damage called Macular Degeneration. For more information about blue light read our blog Blue Light and Your Eyes.
An Anti-Reflective coating is a truly essential component of a quality pair of glasses. If you want to see better, look better, and protect your lenses, you definitely want an Anti-Reflective coating on your lenses.
The last option that we will discuss is tints. Most lenses can be a variety of different colors. Tints can be applied for cosmetic reasons, to block light, or to alleviate medical conditions such as migraines. We’ll discuss 3 types of tints that you may find beneficial: Standard, Photochromic, and Polarization.
Standard tints are generally applied by soaking a lens into a tint color and allowing the lens to absorb the tint. They are available in a variety of colors, and can be applied as a solid or gradient. These tints are the most versatile because of the color and percentage options, however standard tints do not block UV or reduce glare, and are not ideal for sunglasses. If you prefer a tint for cosmetic reasons, or if you cannot wear a polarized lens due to interference with LCD displays, you may choose to wear standard tinted lenses. If you plan to wear your tinted lenses for driving, fishing, golfing, or other outdoor activities, the opticians at Mountain View Optical recommend polarized lenses.
Photochromic tints are designed to change from light to dark when activated by the presence of UV. If you wear your lenses indoors, they will remain clear. When you go outdoors, your lenses will become dark, as long as there is UV in the atmosphere. These lenses are very convenient for people who spend a lot of time outdoors, and don’t want the burden of carrying two pairs of glasses. Recent advances to this technology allows them to change from light to dark faster. It is important to note that because photochromic lenses are activated by UV and not by light, they will not become dark when you are in a car. Most cars have UV blocking tints applied to the windows, which will prevent the lenses from activating. An additional “extra active” photochromic tint was recently introduced to the market. This “extra active” product will darken about 50% behind the windshield, and has a barely perceptible hint of color when indoors. While photochromic tints are a great addition to your lenses, they should not be considered a replacement for sunglasses. For more information about photochromic lenses, and to view demonstrations, visit https://www.transitions.com/en-us/.
Polarization is actually not a tint at all, but a laminate layer applied to the lenses during the manufacturing process. This layer blocks all horizontal light rays from entering your eye. This enhances comfort on a bright day, but also eliminates glare, which is especially helpful when driving or fishing. This layer also filters out 100% of UV rays and reduces blue light, keeping your eyes safe. Polarized lenses do interfere with LCD screens, such as those in newer car displays, and may cause a crosshatch pattern when looking through some car windows. This makes them unsuitable for pilots and those who need to be able to view LCD screens at all times. For most wearers, the benefits will outweigh these concerns.
The board certified opticians at Mountain View Optical are your best resource for information about eyewear. They have over 20 years combined experience fitting and dispensing eyewear, and are truly experts in their field. We hope that this guide will act as a tool to prepare you for working with our staff to find the perfect pair of glasses. Thank you for taking the time to read this article, and stay tuned for more!
Mountain View Optical is currently open by appointment only.
To schedule an appointment, please call or text (907) 328-2920.
Written by: Gina Stafford COA, LDO, ABOC 05/12/2020
Posted in: Patient Education