Traditionally, bifocal and trifocal lenses have been used to correct different prescription powers that are distinctly separated by lines. Bifocals consist of one correction at the top of the lens for your distance vision and one at the bottom to help you read. Trifocals correct faraway, intermediate, and near vision.
As a professional eye care centre in Calgary, we support the use of progressive lenses and prescribe them to many of our clients when appropriate.
How Progressive Lenses Work
Progressive lenses are an intelligent update to bifocal and trifocal lenses, allowing for a seamless transition between prescription powers. This innovative solution for vision problems has rightfully gained popularity in recent years. They are primarily used to correct presbyopia, a common age-related vision condition where the eye's ability to focus on nearby objects diminishes over time.
Progressive lenses work by incorporating multiple vision zones into a single lens without any visible dividing lines. These zones gradually change in power, allowing wearers to see clearly at various distances, including far, intermediate, and near.
Here's how progressive lenses function:
- Distance vision zone - The top portion of the lens is optimized for distant vision. When you look straight ahead or slightly upward, this zone helps you see objects in the distance clearly, like road signs or the television.
- Intermediate vision zone - In the middle portion of the lens, there is an intermediate vision zone. This part is used for viewing objects at arm's length, such as a computer screen or the dashboard of a car.
- Near vision zone - The bottom portion of the lens is designated for near vision tasks, like reading a book or using a smartphone. This part can be used for viewing object as close as your elbow. When you look downward through the lens, this zone comes into play.
- The progressive lens design allows for a smooth and seamless transition between the different zones, simulating natural vision as your eyes move to focus on objects at different distances. Unlike bifocal or trifocal lenses, there are no visible lines on progressive lenses, which makes them more aesthetically appealing and less noticeable to others.
The Benefits of Progressive Lenses
1. No unsightly lines
One of the most attractive benefits of progressive lenses is the gradual change in prescription strength from top to bottom. Unlike bifocals and trifocals, progressive lenses don’t have a sudden jump in prescription strength when crossing a line or border.
They are called progressive lenses because the lens power progresses gradually from the top to the bottom of the lens. This gradual progression of lens power means that there are no unsightly lines on your progressive lenses.
2. No switching between multiple pairs of glasses
Many people have difficulty focusing on nearby objects, a condition known as presbyopia. To compensate for this vision problem, some people need reading glasses as well as single-vision eyeglasses for distance correction. With progressive lenses, you only need one pair of glasses to see clearly at many different distances.
Although presbyopia is more common with age, progressive glasses are sometimes used to correct focus problems in children that prevent the eyes from working together well. Progressive lenses can be designed for patients who are near-sighted, far-sighted, or who have astigmatism. They can be used in sunglasses, blue light-blocking glasses, and photochromic glasses that lighten inside and darken outside.
3. More comfortable experience
25 years ago, 20-30 percent of patients wore bifocal or trifocal eyeglasses because they could not adapt to their progressive lenses or they did not find them comfortable. In our day, progressive lenses are customized and manufactured with the assistance of artificial intelligence.
In this way, your progressive lenses are optimized and customized specifically for your eyes. This makes them far more comfortable than progressive lenses were in the past. Today, there are very few patients wearing bifocal and trifocal lenses because of this fact.
The Different Types of Progressive Lenses
There are several types of progressive lenses available, each designed to cater to different visual needs and preferences. Here are some of the common types:
- Standard Progressive Lenses - These are the most basic type of progressive lenses. They provide the three main vision zones for distance, intermediate, and near vision. Standard progressives offer a smooth transition between the zones, but some wearers may experience peripheral distortion or a narrower reading area compared to more advanced designs. These are the most affordable progressive lenses because they are the least customized.
- Digital Progressive Lenses - Digital progressive lenses are manufactured using advanced computer technology to optimize the lens design and minimize aberrations. These lenses can correct higher-order aberrations that might impact visual clarity in standard lenses, leading to sharper vision and reduced peripheral distortion. This progressive lens design is customized and optimized for a patient’s prescription.
- Freeform Progressive Lenses - Freeform technology uses digital surfacing to create lenses with more precise and complex designs. These lenses are often customized to the individual's prescription for the exact position of the lens in the frames chosen. Since every frame shape is different, the optics of the lens will be different depending on the frame choice. This progressive lens design results in improved clarity and a wider field of vision as well as a similar experience when wearing different pairs of glasses.
- Office Progressive Lenses - These progressive lenses are designed for people who spend a significant amount of time working at a computer or doing other close-up tasks. Office progressives offer a larger intermediate zone, making it more comfortable for prolonged computer use. They also give exceptional near vision for detailed near tasks so this progressive lens design can be used to make wonderful hobby glasses too. However, they may have a smaller distance viewing zone, which likely will not be ideal for driving.
- Occupational Progressive Lenses - Occupational progressives are similar to office progressives but are customized for specific occupations or activities. For example, there are occupational lenses optimized for musicians, mechanics, dentists, and other professionals who require specific vision corrections for their specialized tasks.
- Premium/Customized Progressive Lenses - Premium or customized progressive lenses are tailor-made to suit the individual wearer's specific prescription and visual requirements. These lenses take into account factors such as frame measurements, head position, and reading habits to provide a more personalized and comfortable visual experience. They typically offer larger, clearer, and distortion-free viewing zones, especially in the intermediate and near vision areas. Premium Progressive lenses equalize the magnification of the progressive lenses for differences between the top and the bottom of the lenses, and between the two eyes, making them easy to use, and easy to get used to.
How to Adjust to Progressive Lenses
Adjusting to progressive lenses can take some time, especially if you're new to wearing multifocal eyeglasses. Here are some tips to help make the transition smoother:
- Wear them regularly. The more your use your new progressive lenses, the faster you will get used to them.
- To find the right viewing zone for your different activities, point your nose directly at what you want to see, then move your chin up or down slightly until the thing you are looking at becomes clearly focused. If you hold your reading material in front of you with both hands and your elbows at your sides, your eyes will naturally look through the appropriate near viewing zone.
- To get accustomed to the near vision zone, read books, and newspapers, or use your smartphone regularly. If you need to vary the distance between your eyes and the reading material, remember to tip your chin slightly and you’ll find the viewing zone that matches each distance.
- When you first start wearing progressive lenses, avoid making sudden head movements, as this can cause a momentary blur while your eyes adjust to the new zones. If you have to move your head to look at something in a different position, blink your eyes when you move your head. This blinking sends a “please reset” message to your visual system that helps you ignore the change you experience during head movement.
- Try not to tilt your head too far back when watching TV or driving. Remember, the bottom part of your progressive lenses is for reading.
- If you're experiencing persistent discomfort or visual issues, visit us at Doig Optometry. We can confirm that the lens design is working as it should and we can verify the fit of your frames and make necessary adjustments to improve the alignment of the lenses with your eyes.
Adjusting to progressive lenses is a learning process for your eyes and brain. For most people it takes about 2-5 days. For some people, it can take up to two weeks to feel fully comfortable with a new pair of progressive eyeglasses. Be patient with yourself during the adjustment period. It's normal to have some challenges initially, but with time and practice, you should find your progressive lenses provide clear and comfortable vision for all distances.
If your new progressive lenses are not working after two weeks of wear, please come in for a review with our staff and Doctors. We want you to See Sharp, Look Sharp and Love Your Glasses and most times, a small adjustment in the fit or design of your new progressive lenses will make them work wonderfully.
Book an appointment to take your medical eye care exam in Calgary.