What Is A Progressive Lens?
Progressive lenses are a type of lens with a gradual shift in lens powers. Unlike classic bifocal lenses, there is no sudden image jump from one level of lens power to another. Instead, the transition is smooth, meaning that progressive glasses are often the only ones you need to buy.
Some vendors call progressives "multifocal lenses." Strictly speaking, though, they are different from each other. Unlike single-vision lenses, both offer multiple lens powers. However, multifocals have discrete zones while progressive lenses vary the power continuously across the surface.
Progressive lenses were first introduced in the 1990's as a new prescription lenses product that offers multifocal vision "without the line". Companies realized that aging customers did not like other people seeing the visible bifocal lens line for cosmetic purposes. So the progressive "no-line" lens was invented, and marketed well under the most famous brand name, Varilux. Progressives (sometimes misspelled as progreesive lenses, prograssive lenses, progresive lenses, or pogressive lenses) are named because the lens surface "progresses" from one viewing area to another, erasing the line that is the hallmark of bifocals.
How Do Progressive Lenses Differ From Single Vision Lenses?
You can divide progressives into three zones: distance, intermediate, and reading.
The "distance" section sits at the top of the glasses and corresponds to distance vision. This portion of the glasses kicks in when you're looking straight ahead, perhaps looking out over a landscape.
Next comes the middle portion of a progressive for situations where you need to focus on intermediate distances, such as during a conversation with someone.
At the bottom is the reading portion, similar to a bifocal and offers the highest magnification.
Because of this, progressive glasses can replace three prescriptions of standard single-vision glasses, one of the main reasons why your eye doctor will recommend them.
Interestingly, though, single-vision lenses look the same on the outside as regular lenses. Unlike bifocal lenses, you can't see the different lens powers. They look like one lens.
Are Progressive Lenses The Same As Trifocal Lenses?
The above description makes it sound like progressives are similar to trifocal lenses. After all, both divide vision into three sections.
However, a standard trifocal lens is made differently from a progressive lens. In a trifocal lens, there are three distinct regions for distance vision, intermediate vision, and reading. However, with a progressive lens, there are no visible lines between the sections. Instead, they flow into each other seamlessly.
This factor is one of the main reasons people wear progressive glasses instead of bifocals or trifocals. They want spectacles that function as both reading glasses and distance glasses but without old-fashioned lines on the lens.
But there's another benefit, too: progressive lenses adapt better to different distances. For instance, a person wearing trifocals has to accommodate in-between zones, while someone wearing progressives doesn't. (This problem is even worse for those using bifocals).
Below, we will discuss both the pros and cons of progressives in detail.
Who Is A Good Candidate For Wearing Progressive Glasses?
Anyone can wear progressive glasses but they are best for people living with presbyopia.
People with presbyopia have reasonable distance vision but they struggle to see objects close up, according to the American Optometric Association. The condition prevents the eyes' natural lens from changing shape in the same way as they did when they were young, leading visual clarity to diminish.
People often first become aware of presbyopia when reading books and newspapers. Rather than holding them close up, they notice that they have to read them at arm's length.
Presbyopia symptoms tend to develop slowly as the eyes age, typically after the age of 40. You may be a good candidate for premium progressives if:
You need to hold reading materials at arm's length to improve visual clarity
You have blurred vision at normal reading distances,
You experience headaches and eye strain after doing close-up work (for instance, at a computer screen).
You find close-up work more difficult than before
You want no line bifocals that don't have the bifocal line
You want to wear just one pair of glasses
You want the stylish look of premium progressives
For most people with presbyopia, distance viewing isn't too much of a problem. And, in some cases, the lens might not need to modify your seeing ability at all. However, you will likely need one that lets you see objects that are closer to hand.
In the past, people used bifocals or trifocals for this purpose. But there was a learning curve where people had to train themselves to look directly through the bottom part of the lens, under the bifocal line. With progressive lenses, there is still a learning curve, but the process isn't as awkward.
You should also consider progressives if you have nearsightedness, farsightedness, or astigmatism. These conditions can affect people of any age, including children.
Astigmatism is where your natural eye shape is the wrong shape. Light entering it becomes distorted, causing images to look blurry. Progressive lenses correct this by adjusting incoming light before it hits the surface of the eye.
Near and farsightedness can also be corrected with these glasses. This works in a similar way, though the exact shape of the progressive will depend on your prescription.
What Are The Benefits Of Premium Progressive Lenses?
As alluded to earlier, premium progressives offer multiple benefits compared to traditional bifocals or trifocals, both practical and aesthetic. Here's a list of some of the benefits you can expect by making the switch:
No visible line runs across the front of the glasses, eliminating image jump. This phenomenon occurs when objects abruptly change in clarity and position as the direction of your focus changes from distance vision to near vision. Progressives eliminate the risk of objects shifting in their apparent position because of the gradual change in power across their surface.
More youthful appearance. Both bifocals and trifocals can make people look older because of various associations with these types of lenses. Progressives, though, eliminate this "old glasses'' look and are just as trendy as standard models. New glasses come with attractive frames and eliminate the traditional idea of bifocals.
Improved posture. Bifocals require you to adjust your neck position to direct light through the high-power sections of the glasses, particularly while reading. Because of this, many people wind up with poor posture because they constantly have to crane their necks to see things close to them. The problem is particularly apparent when working at the computer. Wearers have to move in unnatural ways to view all parts of the screen, often tilting their heads backward more than is natural. Premium progressives, however, eliminate this problem. Wearers do not have to adjust their heads as much, making them ideal computer glasses.
Only require one pair. Progressive lenses cost more than standard lenses, but they perform many roles. Instead of having several different prescriptions, you can roll everything into one purchase. Furthermore, you don't have to switch between spectacles. You just put premium progressives on in the morning and you're ready to go. You can see nearby objects without reading glasses.
Reduced eye fatigue. Many people have trouble adapting to bifocals. And that's something that can cause fatigue as the eyes adjust. But with progressive lenses, that's less of an issue.
Pair with contact lenses. If you are someone who wears contact lenses, you can pair them with progressive lenses.
Clear vision at all distances. Lastly, progressive lenses offer clear vision at all distances without visual distortions. Because they have different powers across the lens, you can get everything you need in one prescription.
Adapting To Progressive Lenses
Progressive lenses offer the convenience of multifocals, but without the visible line. However, progressive lenses are much harder to use and to adapt to than bifocal or trifocal prescription glasses, and they are much more expensive. In order to create a no-line progressive lens, there are two large areas of the lens that you cannot see through. Imagine what an hourglass looks like.
This is the shape of the area of the progressive lens that you can see through. Objects seen through the areas of the lens to the left and right of the narrow middle section are highly distorted and you cannot see through them. The bulge areas at the bottom and top of the lens are for near and distance vision, and the thinner corridor connecting them is for intermediate distances.
On either side of the narrow portion of the hourglass objects will appear blurry. In general, more expensive progressive lenses like Varilux lens have a wider corridor, and less expensive lenses have a narrower corridor that can restrict the viewing area considerably. On smaller lens sizes, it is necessary to slice off a portion of the bottom (reading section) of the lens in order to install the lens in the frame. As a result, the smaller the frame size, the smaller will be the reading portion of the lens.
Living With Progressive Lenses
In order to live with progressive lenses, you must learn to move your head to see things; you cannot just move your eyes because you will be looking through a blurry part of the lens. This is called adapting to the lens. Most people can adapt within a month, but some people never adapt. It is common to experience dizziness and headaches during the time that you are adapting. Getting accustomed to progressive prescription glasses can be difficult, and you must have proper instruction by an eyecare professional.
Sometimes, people who try progressive prescription lenses for the first time have a difficult time learning to look through the appropriate portion of the lens at the right time. Often a simple fitting adjustment to your prescription eyewear by your local optical professional can make all the difference.
Fitting Progressive Lenses
To fit progressive lenses properly, the eyeglass frames must first be fit and adjusted to your face. At this point, an optical professional measures the segment height of your lenses. He makes two dots on the lens, one at the bottom edge of your pupil, and the other at the intersection of the lower eyelid and your eye. The measurement in millimeters from the bottom of the lens up to each dot is the segment height. To make any multifocal lens, we must have an accurate segment height measurement. If you send us a pair of glasses with multifocal lenses in them, we can read the lens and determine the seg height and make a perfect copy (re-lensing your glasses). But that segment height is specific to each pair of eyeglass frames and cannot be used for a different pair of frames.
You can ask your local optical professional to measure the seg height for a pair of eyeglasses, and then send them to us with the markings on them. We can then make progressives.
Choosing An Eyeglass Frame For Progressive Lenses
There is only one major restriction on the kind of frame that will accommodate progressive lenses. The eyeglass frame needs to have a height of 30mm or more. Height is referred to as the B measurement of the frame, and is the inside measurement from the bottom to the top of the lens aperture in the frame. If you have fallen in love with a frame that has a B measurement of 27mm to 29mm, there are some new short corridor lens choices that may work for you. Contact Eyeglasses.com customer service for more information.
Are There Any Negatives Of Progressive Lenses?
The drawbacks of progressive lenses are few and far between. However, there are some issues you should be aware of.
First, when you get a new pair of standard progressives, there is an adjustment period. You'll need to train your brain to use different areas of the lens for seeing various distances.
Initially, progressive addition lenses can cause peripheral distortion in your peripheral vision. Images to the side of your visual field look fuzzier than they should because of how the power of a progressive lens varies across the surface.
Your brain will eventually adjust, but it will take at least two weeks, and maybe more. During that time, you may need to refrain from some of your usual activities.
Secondly, progressive lenses tend to cost more than other lenses. That's because the manufacturing process is more complex. Vendors must accurately vary the degree of vision correction according to your prescription across the lens's surface. This process requires specialist machinery and techniques.
With that said, many people find standard progressives are better value because they replace multiple prescriptions. As discussed above, you only need one pair instead of three.
How To Wear Progressive Lenses
If you haven't worn progressive lenses before, it can take some time to adjust to them. Here's how to get the most out of them.
Wear Them As Often As Possible
To get used to your progressive lenses, wear them as often as possible. Remember, these glasses are suitable for nearly all visual situations, so you can use them for both distance and reading. If you don't give your eyes and brain a chance to adjust to them, you won't be able to get the most out of them. Get the right package of lens options to complement your pair.
Follow Your Optometrist's Advice
When it comes to progressive lenses, always follow your doctor's advice. They will tell you when you need to use your progressive lenses and how to wear them in the correct way. Remember, you can always contact them for additional guidance, should you need it.
Aim Your Head In The Direction You Want To Look
When growing up, most of us direct our eyes in the way that we want to look. But when you wear progressive lenses, it is better to move your head. If you move your eyes, then the light will enter them having previously passed through the peripheral areas of the lens, and that may provide the wrong power level.
Look Straight Ahead When Walking
Many people look down at their feet while they walk. But, ideally, you should look straight ahead when wearing progressives.
That's because the bottom section of the glasses is for near-vision tasks, such as reading. If you look down, your feet may appear too magnified, throwing you off balance.
Eye Changes Due to Aging
As you age, so do your eyes. Over time, the lens at the front of the eye loses some of its ability to adjust to looking at objects at different distances.
Fortunately, corrective lenses can accommodate this problem. Optometrists prescribe glasses with the right focal length for your eyes.
But there's a problem. Most people have to buy at least two pairs of glasses: one for everyday situations, and another for tasks that require close-up focus. And that's inconvenient. Constantly taking off one pair of glasses and putting on another is a chore.
Fortunately, with progressive lenses, none of that is necessary. With these lenses, you buy a single pair of glasses for everything, eliminating the cost of multiple prescriptions and adding convenience to your life at the same time.
The History Of Progressive Lenses
French Engineer Bernard Maitenaz invented the first progressive lens in 1959, the first no-line bifocal of its kind. His original product was called the Varilux and its basic concept is still in widespread use today.
Despite the early invention of varifocals, it took some time for pioneers to commercialize them. They only became truly mainstream in the 1990s, and even then, many patients continued to use bifocals or trifocals.
Carl Zeiss launched the Gradal HS progressive lens in 1983. This featured a technology developed by Gerhard Furter called "horizontal symmetry" which changed the behavior of the lens when users looked through it.
Either side of his progressive lens looked the same from the perspective of the wearer, making progressive glasses a more enticing proposition.
Over time, design, production, and acceptance among spectacle wearers improved. Now that the technology is mature, people use it extensively across the globe.
How To Get Progressive Lenses
Are you interested in exploring the benefits of progressive lenses? If so, get in touch with us today. Eyeglasses.com makes getting progressive lenses easy. We offer a range of options, including the latest technologies, giving you a fantastic visual experience.
We strongly recommend that you fax your prescription to us. We can read your prescription and then help find the best prescription eye glasses lens for you. For progressive lenses orders, we require that you fax your prescription to us.
About Your Prescription
Prescriptions have a certain format that is always followed. The first line of your prescription is always for the right eye, sometimes designated the OD. The second line is for the left eye, sometimes designated OS. The prescription for each eye is divided into Sphere, Cylinder, and Axis values. It is common to have no values for any one of these, in which case you might see the letters PL or plano, or to have values for all of these. Sometimes the prescription may say OU which means both eyes.
If your prescription is for bifocals or trifocals of progressive lenses, there may be additional information on the prescription that says for example Add +2.50. This is important information if you are ordering reading or multifocal lenses. The numbers are expressed in diopters that tells the power of the lens. A diopter is a value that is metric and universal worldwide.
On a prescription for multifocal glasses lenses, you will see information designated as add power. Your add power is simply the magnification that is added to your sphere value for distance vision, in order to create a field of view for reading. For example, if your sphere value for distance viewing is 3.00, and your add power is +2.00, then your near vision correction is 1.00. Or, if your sphere value for distance is +1.00 and your add power is +2.00, then your near vision correction is +3.00.