Prescription Eyeglasses
No matter what your eye condition, or how you choose to view the world, there are now prescription lenses that meet your unique lifestyle and vision correction needs. Eyeglass lenses that change as the light changes, from clear indoors to dark outdoors. Bifocal lenses that provide multiple fields of vision. High-index lenses that are thinner and lighter than ever before. And progressive lenses that eliminate the traditional lines of multi-focal lenses. The point is, while eyeglass lenses are prescribed to correct all kinds of vision problems, prescription lenses have come a long way—offering you the opportunity to truly customize your eyeglasses and make a statement about how you choose to look at the world.
Bifocal Lenses
Sometimes our vision fails us at two or even three distinct distances, especially as we age. Bifocal lenses—lenses with two distinct viewing areas—have traditionally been a reliable solution to such a dilemma. (A lens with three distinct viewing areas is called a trifocal.)
By distinct, we mean there are noticeable lines separating the two different fields of vision within a bifocal lens surface. A slight adjustment to the angle of the head allows wearers to choose which lens area to look through based on the distance of the object they’re trying to see.
A farsighted person who also has trouble reading may be prescribed a pair of bifocal reading glasses, for example. The upper section of the lens would correct difficulties seeing objects at distance, and the lower section would assist in reading. (Bifocal glasses date back to the days of Benjamin Franklin!)
While wearers quickly adjust to the line separating the multiple vision fields, it is a noticeable distraction within the lens itself. This line can be eliminated using a newer lens technology called progressive lenses.
Progressive lenses incorporate two, three, or more fields of vision within a single lens without noticeable lens lines. Bifocal, trifocal and progressive lenses are all considered “multi-focal” lenses—lenses that provide correction to multiple vision problems.
High Index and Aspheric Lenses
What are High Index Lenses?
A high index lens is a lens that has a higher “index” of refraction. This means it has a greater ability to bend light rays to provide clear vision for people with stronger prescription glasses. But that’s the technical terminology. What do high index lenses mean for eyeglass wearers?
Thinner, lighter, and more visually appealing, that’s what! High index lenses are manufactured to be thinner at the edges of the lens and lighter in weight overall.
High index lenses are a good option for people who have strong prescriptions for myopia—commonly called “nearsightedness” due to a difficulty in focusing on far objects. A high-index lens can bend light rays more, while using less material in lenses created for both nearsighted and farsighted people (hyperopia).
No more soda bottle glasses
In times past, strong prescriptions meant thicker, heavier lenses, giving some a “glass bottle” appearance. But now, with high index glasses available in thinner, lightweight plastic (as well as slightly heavier glass), lens wearers with stronger prescriptions can get more attractive, yet equally effective, lens products. Because high-index lenses bend light more, anti-reflective (AR) treatment is often recommended as an add-on for optimum clarity of vision.
For better comfort, better vision and improved cosmetic appeal, people with strong prescriptions can’t beat high-index lenses.
Polycarbonate Lenses
Polycarbonate lenses are high index lenses that are known primarily for their exceptional impact resistance and anti-scratch coating. If you or your children are always bumping, scratching or dropping your eyeglasses, this is the material for you. Up to 10 times more impact resistant than standard plastic eyeglass lenses, polycarbonate is a first-rate option for people with an active lifestyle. Developed in the 1970s, polycarbonate has been protecting eyes for quite a while.
Superb Eye Safety
If you regularly engage in sports or physical activity, these tough, durable lenses provide an extra degree of safety for your eyes. In fact, most protective eye gear and sports goggles are made from polycarbonate lenses, even when no vision prescription is needed. In addition, polycarbonate boasts built-in protection from the sun’s UV rays, making this an ideal lens material for time spent outdoors.
Lightweight
The refractive index of polycarbonate lenses is 1.59, which results in a lens that’s 20% to 25% thinner than common plastic lenses. Weighing in at 30% lighter than regular lenses, polycarbonate takes a load off the bridge of your nose!
Trivex Lenses
Developed in 2001, Trivex lenses are constructed from a newer plastic that shares many properties with polycarbonate. While also thin, scratch-resistant, highly impact-resistant and lightweight, Trivex lenses may be slightly thicker than polycarbonate lenses. For some vision prescriptions, they may provide a better visual clarity and more scratch resistance than polycarbonate lenses.
Caring for Lenses
When it comes to prescription lens care, there’s a simple rule that, if followed, will virtually guarantee years of optimum performance from your glasses: If they’re not on your face, then keep your eyeglasses in a case.
Trouble is, no one really follows that simple rule, all of the time. (You know who you are.) If you, like so many of us, don’t always use a solid case to store your prescription glasses, then the following lens care and maintenance tips will go a long way toward maintaining your healthy sight.
Cleaning glasses and protecting your lenses
Keep it clean. Keep it simple. To wash your prescription eyeglass lenses, eye care professionals suggest you gently rub your lenses clean with your fingers using warm, soapy water. Rinse them, and then pat them dry with a clean, soft cloth. Many optical suppliers sell ultra-fine, machine-washable microfiber lens cleaning cloths that trap dirt and dust. Try to avoid rubbing prescription lenses with rags, facial tissues or paper towels, as they could scratch your lenses. And definitely avoid using household cleaners, acetone or soaps with cream—as chemicals may damage your frames.
A strong case for storage
Storing your lenses in a sturdy protective case whenever you are not wearing them will go a long way towards preventing scratches on your lenses. Proper storage also helps to keep prescription eyeglass lenses clean while protecting your valuable frames. Never place prescription glasses in a purse, pocket or bag unprotected.
Let them down gently
Okay. You don’t always use the case. If setting your prescription lenses on a table or desk, it’s best to close your frames first before laying them down. Always set them frame-side down to avoid scratching the lenses. The floor is never a good place to leave your glasses. And when in the bathroom, remember: A sink or vanity top puts your lenses in an unfavorable position. Spatters, sprays and cosmetic products can quickly soil lenses. What’s more, anti-reflective (AR) treatments can be damaged by hairsprays or perfume.
Keep glasses on your nose, not on your head. Prescription eyeglass lenses are designed to rest on your nose in front of your eyes; not on the top of your head. Frames can become misaligned in this manner, making even the cleanest of lenses less than effective if not positioned properly in front of the eye.
Eyeglass Frame Materials
It’s time to choose a new pair of eyeglasses, and the current selection of frames is overwhelming. Armed with only your vision prescription, you now need to navigate between different materials, colors, prices and unique features of all the eyeglass frames. Here is a basic guide that explains about the most common types of frames and what they have to offer.
Metal Frames
The most popular material for eyeglass frames, there is a whole array of metals to consider. Each metal comes with a distinctive set of properties and characteristics.
Titanium
Extremely resilient and corrosion-resistant, titanium is also hypoallergenic and weighs in at 40% lighter than other metals. Available in a variety of color tones, titanium is an ideal material for eyeglasses.
Beta titanium
Titanium mixed with small quantities of aluminum and vanadium, this alloy is more flexible than pure titanium. Adjustments to your eyeglass fit are therefore done easily.
Memory metal
Frames made of memory metal are composed of a titanium alloy that has approximately 50% nickel and 50% titanium. These eyeglasses are very bendable and will return to their original shape even after they are twisted and turned. Memory metal frames are superb for kids or anyone who is rough on their eyeglasses.
Beryllium
The primary advantage of beryllium is its corrosion-resistance. A less costly metal than titanium, beryllium doesn’t tarnish. It is an ideal option for anyone who spends a lot of time around salt water, or who possesses high skin acidity. Flexible, durable and lightweight, beryllium comes in a range of colors.
Stainless steel
Manufactured in both matte and polished, glossy finishes, stainless steel is strong, flexible, corrosion-resistant and lightweight. An iron-carbon alloy, it also contains chromium.
Monel
This popular alloy of copper and nickel is less expensive than other metals, yet depending upon the quality of plating used – it sometimes discolors or causes skin reactions after long use.
Aluminum
Lightweight and very resistant to corrosion, aluminum boasts a unique look and is frequently used in high-end, exclusive eyewear.
Plastic Frames Zyl
Abbreviated from “zylonate” (cellulose acetate), zyl is relatively inexpensive and very popular in plastic eyeglass frames. Lightweight, it is available in a rainbow of colors, including multi-colored versions and layers of different colors within one frame.
Propionate
Often used in sports frames, propionate is extremely durable and flexible. This nylon-based plastic is also lightweight and hypoallergenic.
Nylon
Over recent years, nylon has been replaced largely by more resilient nylon blends, such as polyamides, gliamides and copolyamides. While 100% nylon is lightweight and strong, it tends to weaken with age and become brittle.
Cellulose acetate
A plant-based plastic that is hypoallergenic. This material was first used for eyewear in the late 1940’s because of brittleness and other problems with previously used plastics. Today’s acetates are known for being strong, lightweight, and flexible. Cellulose acetate also has the widest range for transparency, rich colors, and finishes. More complex colorations are able to be produced by layering several colors or transparencies in layers and sandwiching them together.
Combination Frames
The best of both worlds, combination frames offer metal and plastic components in one frame. These styles were trendy in the 1950s and 1960s and have recently been revitalized for a fun comeback in many more colors and tones than the classic versions.
Mix It Up!
Each respective frame material brings unique features and advantages to your eyeglasses. One pair of glasses may not fit every part of your daily routine, in addition to social outings and special occasions. Perhaps a pair of titanium frames is best for your sophisticated, conservative work environment, but on the weekends you’d prefer to show off style with a retro zyl frame in laminated colors? Consider purchasing more than one pair of eyeglasses, and match your frames to your personality and lifestyle.
Frame Maintenance
Your eyeglass lenses are designed to correct your vision based on being held firmly in a fixed, stable position in front of your eyes. So when it comes to your eyeglass frames, it’s pretty easy to see why frame protection and maintenance is so important.
Many of us don’t realize how critical proper eyeglass frame alignment really is. But it’s why our eye care professional checks and double checks the position of our eyeglass frames in relation to face shape and size. The correct part of the lens needs to align properly in front of the eye for ideal vision correction.
Eyeglass frame protection maintenance isn’t time consuming—but it is a common sense, routine task you can perform to keep your vision in the clear. Here are tried-and-true ways to keep your eyeglass frames in mind. And in place.
Caring for eyeglass frames
Both hands, please! Eye care professionals suggest using both hands when putting on and taking off your glasses to avoid twisting or misaligning them. Gently grasp the frame arms of your glasses with equal pressure and carefully slide them on, lifting them over your ears. Use the same grip to remove them, sliding them up and forward.
Pay attention. When was the last time you actually took a good look at your frames? Periodically check your eyeglass frames to see if they are misaligned, and to test for loose screws in the frame arms. If the eyeglass frame looks twisted, or if your lenses seem to ride uneven on your nose, then it’s time to drop in on your eye care professional for a (typically free) adjustment. In addition, many drug stores sell inexpensive eyeglass tool kits containing a small screwdriver and an assortment of temple screws for emergency repairs.
Adjust early, adjust often. It’s a good idea to stop by your neighborhood optician to have your eyeglass frames adjusted. Many opticians will re-adjust your frames, whether you purchased your glasses from them or not. Even a slight adjustment can make an important difference in your healthy sight.
Don’t try this at home. Adjusting your eyeglass frames is not a do-it-yourself job. Your eye care professional is trained to know how your lenses need to be positioned relative to your eye. Also, an eyeglass frame can contain fragile materials and design elements. You might just snap them in your effort to fix them. That means no bending of frame arms!
Don’t forget to wash. Just as you need to wash your lenses, you need to wash your eyeglass frames. Regularly. With soapy water and a soft cloth.
Not on your head, not on the floor, not by the sink… Storing eyeglass frames on your head can stretch and misalign them. Stepping on your glasses is the quickest way to twist them or break them. And the bathroom sink is a good recipe for soiled lenses as well as frames. Sturdy eyeglass frame cases exist for good reason.
Special thanks to the EyeGlass Guide, for informational material that aided in the creation of this website. Visit the EyeGlass Guide today!