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Cover Stories | May 2024

The Art of Explaining Presbyopia-Mitigating IOLs

Strategies for effective patient counseling.

Several new advanced technology (AT) refractive IOLs have become commercially available in recent years. The multitude of good choices is a double-edged sword—it has become more difficult than ever for us to explain the options concisely to patients and for them to decide what they want. As surgeons, we know that the most important determinant of patients’ postoperative satisfaction is preoperative counseling. The premium payment raises patients’ expectations; uninformed, inaccurate, or unrealistic expectations pose a significant risk of patient dissatisfaction after surgery. As busy ophthalmologists, we need preoperative counseling to be both efficient and effective. When a patient is confused or cannot remember something we just explained, it can be hard to feel empathetic if we are behind schedule during a hectic clinic day. Instead, we become impatient and frustrated, and over time, we may feel burnt out by the process.

It is important for us to realize how confusing and stressful the process of selecting an IOL has become for cataract patients. A variety of multifocal and extended depth of focus (EDOF) IOLs, a pseudoaccommodating IOL (Crystalens/Trulign, Bausch + Lomb), enhanced monofocal IOLs, and standard monofocal IOLs are available. We can offer micro-, mini-, and full monovision, and then we must explain toric correction and adjustability. The value proposition of these different IOLs and strategies involves optics and other concepts (eg, presbyopia, astigmatism, contrast sensitivity, anisometropia, binocular depth perception, focal distance, and depth of focus) that are difficult for many patients to comprehend. Many of the options have side effects and involve trade-offs that the patient cannot test in advance. Even with trifocal IOLs and varying degrees of monovision, we are not able to guarantee that a given patient will never need spectacles. Add to this all the cautionary stories that their friends have shared about an IOL for which they paid extra, and it is no wonder that some overwhelmed patients ask me if they can just have cataract surgery without a lens implant!

Here are some educational strategies that I have developed after counseling thousands of patients during the nearly 2 decades since the 2005 CMS decision to permit patient-shared billing for ATIOLs.

Eyesight Is Not Binary

I first explain that every cataract patient receives one of three types of lens implant: single focus, extended focus, or multiple focus. I avoid saying monofocal because this term can be confused with monovision. I add that we can incorporate astigmatism correction if necessary—the toric feature—into any type of lens implant. Instead of calling it standard, I refer to a nontoric monofocal IOL as the basic, single-focus lens.

After learning about ATIOLs, patients often make the following comments:

  • “So, I won’t need any glasses?”
  • “So, I won’t need reading glasses?”
  • “Will I see 20/20?”
  • “I don’t mind distance glasses, but I want to read well without glasses.”

They become frustrated and confused because we cannot respond to these reasonable remarks with a simple yes or no. The challenge is that patients tend to think simplistically in binary terms—glasses or no glasses, near vision or far vision, 20/20 or not. It is crucial for them to understand that eyesight is not binary but rather a continuum of quality and focus. To illustrate this, I invoke the grading system commonly used in school: A = perfect, B = good, C = passable, D = poor, and F = legally blind.

If an individual referred with a brunescent cataract says, “I still see fine,” I may explain that their vision is currently a C+ or B- but should be an A or A- after cataract surgery. To discuss the implications of an epiretinal membrane detected with preoperative macular OCT, I might say, “You probably won’t have an A, even with eyeglasses, following cataract surgery, but your vision will probably be quite good, a B or B+.” If a patient questions why they would want to pay extra for a multifocal IOL if they will still have to purchase and wear readers, I explain that, if they dislike cold weather, they would likely be very happy moving from Minneapolis to San Diego even if they still occasionally have to wear a sweater or jacket.

Explaining the Defocus Curve

To understand the functional benefits of different ATIOLs, we evaluate their defocus curves. To convey to patients that, like eyesight, focus is a continuum, I explain that the eye is like a camera and we all need to see at four different zones:

  • Zone No. 1 is far distance vision (street signs, golf ball, TV captions, sporting events);
  • Zone No. 2 is indoor distances (our kitchen walls, faces across the dinner table);
  • Zone No. 3 is arm’s length (desktop computer screen, dashboard, store shelves, bathroom mirror); and
  • Zone No. 4 is reading distance (menu, cellphone, laptop screen, tablet).

I have basically explained the defocus curve with the four zones essentially corresponding to plano, -1.00 D, -1.75 D, and -2.50 D. I explain that, when people are young, they have an autofocus camera thanks to the human lens, which automatically changes focus without people’s being aware that it is happening. They gradually lose this ability with age until they end up with a manual focus camera in their 70s. They may have to switch between three different pairs of spectacles to move the camera’s focus back and forth between far and near. Many people accept the side effects of progressive trifocals to avoid this inconvenience.

It is important to explain the type of focus the patient currently has without glasses. If they brag about being able to read well up close (eg, -6.00 D of myopia), I explain that this is because their camera is set to zone No. 7 but that this makes the four most commonly needed zones blurry. The camera analogy helps me explain a monofocal IOL target of -1.00 D (zone No. 2) to someone with lifelong myopia, because targeting zone No. 1 may make zone No. 4 distressingly blurry. I can explain that having one eye at zone No. 1 and the other at zone No. 4 is true monovision—the eyes are divorced and only work alone; however, with blended vision (zone No. 1/zone No. 2), the two eyes still work together. An EDOF IOL covers three out of four zones, and a multifocal IOL covers all four. I know patients understand when they ask if they can target zones No. 2, 3, and 4 with an EDOF IOL instead of zones No. 1, 2, and 3. I explain that, unfortunately, no IOL can provide grade A focus across all four zones, so I cannot restore the vision they enjoyed in high school. With a multiple focus lens (eg, trifocal IOL), however, they can expect to have very good (grade B+) far vision and good (grade B) vision for zone Nos. 3 and 4.

“With adequate lighting,” I say, “you can see well at these zones (desktop computer, cellphone), but you may wear readers to achieve an A for zone No. 4 for challenging tasks such as sewing, seeing small print, or prolonged reading.”

Explaining Probability

I use the analogy of putting a golf ball to convey probability when explaining that I cannot guarantee a precise refractive outcome. Optometrists fitting contact lenses can keep trying different powers (like taking multiple putts) until the patient’s distance visual acuity has been optimized. Because cataract surgeons get only one putt, perfect (grade A) distance vision without glasses is possible, but patients often end up with grade B+ (very good). Their need for distance glasses (to achieve an A), such as for freeway driving at night, is infrequent. To patients who have undergone LASIK, I explain that their surgically altered corneas make my job akin to putting on an unevenly sloped green instead of a flat green. They could end up with C+ distance vision without glasses, which would become an A with glasses. The Light Adjustable Lens (RxSight) gives us up to three extra putts.

Emphasizing Compromise

It is crucial for patients to understand that maximizing their spectacle independence always involves some compromise. They are much more likely to accept and rationalize the compromises if they understood them preoperatively. An example is someone who has historically enjoyed good binocular distance visual acuity and dislikes trifocals and reading glasses but also does not want to see halos at night. I suggest that they weigh which would bother them more—rings around lights only at night, such as during the winter months, or frequently grabbing readers to view their cellphone. In other words, it is an individual lifestyle decision, and there is no choice that is right or wrong for everyone.

I also explain the contingency of implanting a nondiffractive EDOF IOL in their second eye if they are really bothered by halos in their first eye and that less than 10% of my multifocal IOL patients elect this option.


Having to repeatedly explain this basic information to every cataract patient is a recipe for burnout and hardly the best use of our surgical and cognitive skills. In addition to explaining concepts in my handouts and on my website, I have recorded videos in which I provide this fundamental information (Figure). Cataract patients are directed to the videos and handouts on my website in advance of their consultation. These materials are also provided to them while their pupils are being dilated in the office. Patients regularly compliment me on the camera analogy and how much better they understand their options as a result.

Figure. Patient education video on Dr. Chang’s website in which he uses a camera analogy to explain the differences between the refractive IOL options.

Finally, I now encourage patients to use the voice recording app on their phones to record our consultative discussion. I find this improves their comprehension and retention of information, allows other family members to listen to the explanations later, and reduces miscommunication and the number of additional phone calls and questions.

David F. Chang, MD
  • Clinical Professor, University of California, San Francisco
  • Private practice, Los Altos, California
  • Editor Emeritus, CRST
  • Member, CRST Global | Europe Edition Advisory Board
  • dceye@earthlink.net
  • Financial disclosure: Consultant (Alcon, Carl Zeiss Meditec, Johnson & Johnson Vision, RxSight)
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