The advantages: Progressive vs. Bifocal lenses for vision over 40
No one likes to advertise their age — especially when you're 40-something and having trouble reading fine print.
Thankfully, today's progressive lenses make it impossible for others to tell you've reached the age where you have to grab reading glasses.
Progressive lenses — they sometimes used to be called "no-line bifocals" — give you a more youthful appearance by eliminating the visible lines found in bifocal lenses. Premium progressive lenses (such as Varilux lenses) usually provide the best comfort and performance.
Beyond being just a lens with no visible lines, modern progressive lenses enable people with presbyopia to again see clearly at all distances and offer a myriad of benefits.
Advantages of progressive lenses over bifocals
Bifocal lenses have only two powers: one for seeing across the room and the other for seeing up close. Objects in between, like a computer screen or items on a supermarket shelf, often remain blurry with bifocals.
As they can't see objects at this "intermediate" range clearly, bifocal wearers have to bob their head up and down, and crane their neck forward, in an attempt to get a focus with their lenses.
Bifocals also put you at risk of computer vision syndrome (CVS) when using a computer for extended periods. Bifocal wearers have to sit closer to the screen and tilt their head back and jut their chin forward to see through the bottom part of their lenses. This unnatural posture leads to muscle strain, neck pain and other symptoms of CVS.
Progressive lenses closely mimic the natural vision that you enjoyed before the onset of presbyopia. Instead of providing just two lens powers like bifocals (or three, like trifocals), progressive lenses are true variable focus lenses that provide a smooth, seamless progression of lens power for clear vision across the room, up close and at all distances in between.
With progressive lenses, there's no need to bob your head up and down or adopt uncomfortable postures to see your computer screen or other objects at arm's length.
Holding your head in a comfortable position, you can simply look straight ahead to see in the distance, move your eyes slightly downward to view your computer through the intermediate zone and lower your gaze a bit farther to read comfortably up close.
Natural vision with no "image jump"
The lines in bifocals and trifocals are points where there's an abrupt change in lens power.
When a bifocal or trifocal wearer's line of sight moves across these lines, images suddenly move, or "jump." The discomfort caused by this "image jump" can range from being mildly annoying to creating nausea. At its worst this jump is simply dangerous, creating a higher risk for falls as wearers negotiate, stairs, escalators and kerbs.
Also, due to the limited number of lens powers in bifocals and trifocals, your depth of focus with these lenses is limited. To be seen clearly, objects must be within a very specific range of distances. Objects that are outside the distances covered by the bifocal or trifocal lens powers will be blurred.
Progressive lenses, on the other hand, have a smooth, seamless progression of lens powers for clear vision at all distances. Progressive lenses provide a natural depth of focus with no "image jump."
It's important to note, that the first time you wear progressive lenses, you may notice a soft focus in your peripheral vision through the lower half of the lenses, to the right and left of the intermediate and near zones.
Typically as you wear and learn to use your progressive lenses this sensation will go away. If it persists, tell your optometrist. (If necessary, a slight adjustment will usually solve the problem.)
Progressive lenses for all frames and lifestyles
With all their visual and cosmetic advantages over bifocals, progressive lenses have become the most popular lenses for anyone with presbyopia who wears glasses.
This demand has led to a number of recent advances in progressive lens technology, including:
Wider zones of clear vision
Some very early progressive lens designs (30 to 50 years ago), had some limitations in lateral field of view for computer use and reading.
Today's modern progressive lenses, have greatly increased the size of the zones for computer use and reading. For computer users, there are special occupational designs (also known as extended focus lenses) that greatly expand the intermediate zone for enhanced comfort at the computer.
More comfort for active wear
With early progressive lens designs, first-time wearers could experience the sensation of movement or "swim" during quick head turns.
Advances in computers means today's progressive lenses have superior optics and fewer peripheral aberrations, making them very comfortable for active wear. Some of the newest high-definition lens designs found in modern digital progressive lenses are created with, for example. the same wavefront-guided technology used in LASIK surgery for crystal-clear optical performance over a wide field of view. New ditial
Compatibility with a wide choice of frames
Today, many progressive lenses have flexibility in their designs meaning they can made for a wide range of frames form smaller sizes to the large fashion frames. With these new designs, virtually all wearers who want a fashionable frame of their choice can enjoy all the benefits of progressive lenses.
Better lens materials
Today's progressive lenses are available in all the latest lens materials, making them thinner, lighter and more comfortable than ever before.
Progressives made of high-index plastic lens materials can be up to 50 percent thinner than standard plastic bifocals.
For safety eyewear, many brands of progressive lenses are available in lightweight and impact-resistant polycarbonate as well.
Other options for progressive lenses
For the best vision, comfort and appearance, purchase anti-reflection (AR) coating for your progressive lenses.
AR coating virtually eliminates distracting lens reflections that cause ghost when driving at night. It also makes your lenses nearly invisible, for better eye contact with others and a more attractive appearance.
For outdoor wear, many of today's progressive lenses are available in a wide range of photochromic tints, including Transitions Style Colours, for greater comfort when going in and out of the sun. Many premium progressive lenses are also available as polarised sunglasses.
Seek expert advice for your best lens choice
With so many progressive lens designs and options available today, the choices can be easy with professional advice.
To make a wise investment and to get the progressive lenses that work best for you, consult with your optometrist. A knowledgeable eye care professional will be able to recommend a truly customised progressive lens solution for your lifestyle and visual needs, and give you helpful tips about learning to use and care for your first pair of progressive lenses.
Page published on Tuesday, 17 March 2020