Written By: Reena Mukamal for the AAO.org
Your eyes change as you age. When you reach your 40s, don’t be surprised if it becomes difficult to adjust your focus between a book, a website on a computer screen and the conference room whiteboard. Progressive lenses are growing in popularity among people who need help seeing near, far and in-between.
What is a progressive lens?
These eyeglasses have seamless increase in magnification from the top to the bottom of the lens, helping you see clearly at all distances with just one pair of glasses. You look through the top portion of the lens to see far-away objects, the middle to focus on intermediate objects and the bottom to see things close-up. The prescription changes little by little across the lens surface, providing a gentle transition.
This may be especially useful to people who wear single-vision eyeglasses for distance (due to nearsightedness, farsightedness or astigmatism) in addition to reading glasses for near work (due to presbyopia).
Are progressives the same as trifocals?
No. Bifocal and trifocal lenses have two or three different magnification levels, separated by a visible line. Progressives lack these telltale transition lines. In fact, many people prefer progressives because they do away with the old-fashioned lines found on bi- and trifocals.
But the seamless transition is important for another reason: The smooth transition between close-up and far-away viewing avoids the “image jump” that people experience with bifocals or trifocals. This is where objects abruptly change in clarity and apparent position as your eyes move across the prescriptions in the lens.
People who do a lot of computer work may benefit from computer glasses, a subset of progressives that devote more space on the lens to intermediate distances. Computer glasses have a correction specifically designed for focusing on computer screens, which are usually positioned about 20 to 26 inches away from the face. Computer glasses can help reduce eyestrain and eye fatigue and allow you to more easily switch your focus between whiteboards, printed pages and computer screens.
Drawbacks of progressive lenses
These all-in-one glasses have a learning curve. Without a visible line to guide you, you’ll have to train yourself to look out of the correct portion of the lens for the task you’re performing. You’ll need to train your eyes to look through the top (distance) portion of the lens while walking. If you’re walking up stairs and look down through the lower portion of the lens, your feet may appear larger than they are.
Progressive lenses can also cause peripheral distortion when moving your eyes from side to side. During the learning period, you may feel off-balance or even nauseated from looking through the wrong section of the lens.
Cost is also a factor. Progressive lenses are significantly more expensive than single or multi-focal glasses because of the extra time that goes into creating a lens with multiple prescriptions and no lines.
Adjusting to progressive lenses
It might take anywhere between a week to a couple of months to adapt and learn the correct way to look through the lens. To reduce the adjustment time, make sure to have your lenses customized and fitted by a licensed ophthalmologist or optometrist, and wear them as often as possible. Point your nose toward the object you’re focusing on and adjust your chin up or down until the object appears clear. If you experience eye strain or headaches, it’s okay to take breaks and remove your glasses, but do keep trying.