The Eye Show • EyeDoc2020
What Is the Best Cataract Surgery and Intraocular Lens for You?
It remains the best time in the history of the world to have cataract surgery. Our complication rates are incredibly low. In my hands, the femtosecond laser has helped lower my complication risk even further, close to zero in routine cases, though no eye surgery is ever completely without risk.
What the femtosecond laser is, and who it is for
The femtosecond laser is a computer-guided laser that performs several of the most delicate steps of cataract surgery with a precision the human hand cannot match. It maps your eye and then makes its cuts in a fraction of a second, which is where the name comes from.
Think of the cataract as a cloudy pillow sitting inside a pillowcase. The laser opens the front of the pillowcase in a clean, perfectly round window and divides the cloudy pillow into small pieces. We then vacuum those pieces out with an ultrasound handpiece called phacoemulsification. Because the laser does so much of the fine work up front, many patients wake up the day after surgery with a beautifully clear cornea, and are usually very happy compared with standard surgery.
Who is, and is not, a candidate for the femtosecond laser
| Good candidate | Not ideal, or proceed with caution |
|---|---|
| Routine cataract surgery | Cannot lie flat or hold still |
| Astigmatism that benefits from precise laser incisions | Very small or poorly dilating pupil |
| Choosing a premium or adjustable lens where centration matters | Cornea scarred or cloudy enough to block the laser beam |
| Able to fixate for a short time; pupil dilates well | Very dense cataracts, prior surgery, deep-set eyes, or narrow lids |
When the laser is not the right fit, standard manual cataract surgery is often the safer choice.
Why the implant is the hardest decision
Everyone who has a cataract removed needs an implant, called an intraocular lens, or IOL. Everyone should have one. Without it, you would need Coke-bottle-thick glasses to bend the light coming through your pupil onto your macula. There is no perfect implant, but the technology has improved dramatically, and choosing well is where most of the thinking happens.
The risks, in plain numbers
Every surgery carries risk. Incidence means how often something new happens in a group of people over a period of time. A 2 percent incidence means about 2 people in 100, or 20 in 1,000. The serious risks are rare. The most common issue today is needing a YAG laser capsulotomy to clear the back of the pillowcase, and the second is simply the need for glasses. I wear glasses myself and cannot wait to have my own cataract surgery one day.
| Risk | General incidence | What changes it for a long, myopic, glaucomatous eye |
|---|---|---|
| YAG capsulotomy | ~30% over time | Similar; unrelated to lens power[1] |
| Pressure (IOP) spike after surgery | ~10% ordinary eyes; ~28% in high myopia | Glaucoma raises it further; ~5% of glaucoma eyes spike above 30 mmHg[2][3] |
| Retinal detachment | ~0.4–2.9% over 10 years generally | ~9.5% over ~5 years in men under 60 with eye length ≥25 mm; up to 25× a non-myopic older eye[4][5][6] |
| Retinal detachment, per millimeter | — | Risk rises ~42% for every extra millimeter of eye length[4] |
| Refractive surprise (power off target) | Small in normal eyes | Only ~61% of very long eyes land within 1.0 D; a hyperopic shift is common[7] |
| Capsular contraction / lens dislocation | Low | ~2.1% contraction, ~0.58% dislocation in high myopia[8] |
| Toric lens rotation losing correction | — | Each 1° of rotation loses ~3.3% of the correction (see toric chart below)[9] |
So which lens should you choose? Start with two questions
Would I be OK needing progressive glasses?
Would I be OK needing readers?
If the answer to both is yes, then the lens your insurance covers, the monofocal, is the best option, and currently it is the only one insurance pays for.
If the answer is no (and for me it is no), ask two more questions.
Do I drive at night?
Would I mind halos and glare around lights, especially at night?
If yes (and for me it is yes on both), avoid multifocal implants such as PanOptix Pro, Symfony, and Synergy, and focus on the Light Adjustable Lens.
Astigmatism, and why toric rotation matters
Even 0.50 D of astigmatism can blur vision enough to send you back into glasses. A toric lens corrects astigmatism only while it stays in the exact orientation we set, so rotation is a central reason I lean toward the Light Adjustable Lens for significant astigmatism.
| Toric lens rotation | Effect on the astigmatism correction |
|---|---|
| Each 1° | Loses about 3.3% of the correction[9] |
| Under 10° | Refraction changes less than 0.50 D, usually acceptable[9] |
| 10° | About a third of the correction is gone; vision meaningfully affected[9] |
| 30° | Correction completely nullified[9] |
| 45° | Essentially no correction remaining[9] |
| Modern toric stability | Average rotation only ~2.36° across 4,863 eyes; ~0.77% ever need repositioning[9] |
Modern torics are stable on average, but a single lens can still rotate, and the Light Adjustable Lens sidesteps the issue by correcting astigmatism with light after healing, with nothing to rotate.[9]
What is the axial length of each eye?
Axial length is the front-to-back length of the eye in millimeters. It decides which lens powers are available and how much retinal risk you carry.
| Axial length | Meaning |
|---|---|
| ~23–24 mm | Average eye |
| ≥26 mm | High myopia; higher retinal and refractive risk |
| ≥28 mm | Threshold of pathologic myopia; retina evaluation often wise first |
Lens types, explained simply
| Lens type | What it does | Halos / glare | Glaucoma friendliness |
|---|---|---|---|
| Monofocal | One focus point, like a camera set to one distance | None | Best |
| Enhanced monofocal (refractive) | Smoothly bends light with a small intermediate boost | Minimal | Favorable |
| Light Adjustable Lens (refractive) | Monofocal you can fine-tune with light after surgery | None | Favorable |
| Multifocal (diffractive) | Splits light into 2–3 focus points with tiny rings | Highest | Avoid in moderate/advanced |
Refractive versus diffractive, in plain language
Imagine light entering your eye as a stream of tiny balls that must land on one spot at the back to make a sharp picture. A refractive lens bends the whole stream smoothly to that spot, like a plain magnifying glass. A diffractive lens has many tiny stair-step rings that split the stream into two or three smaller streams at once, sending some light near and some far. That split is how it gives distance and near without glasses, but each spot gets less light, and the leftover scattered light makes halos and glare around lights, worst at night.
Why this matters in glaucoma and macular disease
In moderate to advanced glaucoma, the optic nerve is already damaged and already losing sensitivity to contrast and light, and in macular disease the central retina is already stressed. A diffractive lens further reduces and scatters the light reaching the retina, which worsens vision for these patients and can even interfere with the visual field tests used to monitor glaucoma. That is why I avoid diffractive multifocal lenses in moderate and advanced glaucoma and in significant macular disease.
The full U.S. lens comparison chart
Here is every major refractive and diffractive option available in the United States, including the monofocal and Light Adjustable options, showing which lenses are generally acceptable or not acceptable in glaucoma and in macular disease. Green means generally suitable, amber means select or mild cases only, and red means generally not recommended. The percentages are approximate general estimates and are not guarantees.
| Lens | Company | Type | Glaucoma | Macular disease | Halos / glare | Distance (no glasses) | Intermediate (no glasses) | Near (no glasses) | Satisfied | Power (D) | US usage (approx.) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Monofocal (standard) | alcon / j&j / b+l | Monofocal | OK | OK | None | ~85–90% | ~15–25% | <10% | ~90% | −10 to +40 | ~75–80% of all IOLs |
| TECNIS Eyhance (+Toric II) | j&j | Enhanced monofocal | OK | OK | Minimal | ~85–90% | ~40–60% | ~10–20% | ~90% | +5 to +34 | Common |
| enVista Aspire | b+l | Enhanced monofocal | OK | OK | Minimal | ~85–90% | ~40–60% | ~10–20% | ~90% | +6 to +34 | Growing |
| RxSight LAL | rxsight | Adjustable monofocal | OK | OK | None | ~92–96%* | ~20–30% | <15% | Very high | −2 to +30 | Fast-growing premium |
| RxSight LAL+ | rxsight | Adjustable (broadened) | OK* | OK | Minimal | ~92–96%* | Good | Limited | Very high | −2 to +30 | New, growing |
| Clareon Vivity | alcon | Non-diffractive EDOF | Caution | Caution | Low | ~85–90% | ~70–80% | ~20–40% | ~90% | +15 to +25 | Common EDOF |
| TECNIS PureSee (+Toric II) | j&j | Refractive EDOF | Caution | Caution | Low | Excellent | Very good | Limited | 97% rec. | +5 to +34 | New (2026) |
| TECNIS Symfony OptiBlue | j&j | Diffractive EDOF | Caution | Caution | Moderate | Excellent | Excellent | Functional | High | +5 to +34 | Declining |
| Clareon PanOptix | alcon | Diffractive trifocal | Avoid | Avoid | Moderate | ~85% | ~85% | ~85% | ~90%+ | +6 to +34 | Leading trifocal |
| Clareon PanOptix Pro | alcon | Diffractive trifocal | Avoid | Avoid | Moderate | ~85–90% | ~85%+ | ~85% | High | +6 to +34 | New flagship |
| TECNIS Synergy | j&j | Diffractive full-range | Avoid | Avoid | High | Good | Excellent | Excellent | High | +5 to +34 | Niche |
| enVista Envy | b+l | Diffractive trifocal | Avoid | Avoid | Moderate | Good | Good | Good | High | +6 to +34 | Newer trifocal |
| TECNIS Multifocal (ZMB/ZLB) | j&j | Diffractive bifocal | Avoid | Avoid | Mod–High | Good | Poor | Good | Moderate | +5 to +34 | Legacy / low |
Green = generally suitable; amber = select or mild cases only; red = generally not recommended. * LAL is on-target after light adjustment; LAL+ has favorable monofocal-style optics but limited glaucoma-specific data. Powers and availability from manufacturer data: PureSee +5.0 to +34.0 D (FDA March 2026, Toric II for ≥1 D astigmatism); PanOptix Pro +6.0 to +34.0 D; RxSight LAL and LAL+ −2.0 to +30.0 D.[10][11][12]
Who should, and should not, choose each family
| Lens family | Who should consider it | Who should not (in general) | Main risks |
|---|---|---|---|
| Monofocal | Anyone, especially glaucoma or macular disease, night drivers, and those comfortable with readers or progressives | Those who want to be glasses-free for near and intermediate | Will need glasses for near |
| Enhanced monofocal (Eyhance, enVista Aspire) | Want a little more intermediate while keeping monofocal safety; glaucoma; mild macular disease | Want true reading vision without glasses | Still need readers for fine print |
| Light Adjustable (LAL, LAL+) | Astigmatism, high myopia, prior LASIK/PRK, glaucoma, and anyone wanting the most precise final result | Cannot wear UV glasses for 2–3 weeks or attend several extra visits | UV eyewear until lock-in; multiple adjustment visits |
| Refractive / non-diffractive EDOF (Vivity, PureSee) | Want intermediate with few halos and near-monofocal contrast; healthy eyes or only mild disease | Moderate or advanced glaucoma or macular disease; want strong reading vision | Readers for fine print; toric versions can rotate |
| Diffractive EDOF (Symfony) | Want continuous distance-to-intermediate range | Glaucoma or macular disease; halo-sensitive night drivers | Night halos; near often needs readers |
| Diffractive multifocal (PanOptix, PanOptix Pro, Synergy, enVista Envy, TECNIS Multifocal) | Healthy eyes wanting the widest glasses-free range | Moderate or advanced glaucoma, macular disease, or anyone bothered by night halos | Halos and glare, reduced contrast, and interference with glaucoma visual-field testing |
This chart is also provided as a color image you can post directly (file: IOL-comparison-chart.png).
A real-world example
Consider a patient born in 1966 with a lifelong history of myopia and moderate glaucoma. She drives at night and wants good distance, intermediate, and near vision, and is comfortable using glasses for some tasks. She is interested in the LAL+, the PureSee, and the Eyhance Toric II.
| Measurement | Right eye (OD) | Left eye (OS) |
|---|---|---|
| Axial length | 27.42 mm (high myopia) | 28.04 mm (threshold of pathologic myopia) |
| Corneal astigmatism | 1.70 D @ 81° | 1.05 D @ 105° |
| Optic nerve | Moderate glaucoma, thinned nerve fiber layer, reduced contrast sensitivity | |
A note from the RxSight team on this patient's biometry
Every RxSight lens (LAL and LAL+) is available from −2.0 D to +30.0 D, in 1 D steps below +16 D. Running this biometry through the Barrett formula (A-constant 119.1) gives about 9 D in the right eye and 8 D in the left, each chosen closest to plano, both predicting a +0.16 D spherical equivalent. Converting to predicted glasses numbers gives OD −0.69 +1.70 × 081 and OS −0.36 +1.05 × 105. Because the light-delivery device can flatten by about 3.25 D and steepen by about 4 D, the entire astigmatism can be treated after healing in the right eye, with even more room to spare in the left.
The biometry, and why the LAL+ fits beautifully here
This updates my earlier estimate. Far from being limited by lens power, the LAL and LAL+ come in exactly the low powers these long eyes need, and the light adjustment has ample range to correct all of her astigmatism after the eye has healed, with nothing to rotate.
| Parameter | OD (AL 27.42 mm) | OS (AL 28.04 mm) |
|---|---|---|
| Barrett-recommended LAL power | 9.0 D | 8.0 D |
| Predicted spherical equivalent | +0.16 D | +0.16 D |
| Predicted glasses prescription | −0.69 +1.70 × 081 | −0.36 +1.05 × 105 |
| Meridians (M1 / M2) | −0.69 / +1.01 | Lower cylinder, same pattern |
| Available power range | −2.0 to +30.0 D (1 D steps below +16 D) | Same |
| Light adjustment headroom | Flatten ~3.25 D, steepen ~4 D → entire cylinder treatable | Same, with room to spare |
The three lenses she asked about, compared
Chart 1. LAL+ versus Eyhance Toric II
| Feature | LAL+ | Eyhance Toric II |
|---|---|---|
| Optical mechanism | Increased central power (refractive) | Continuous aspheric power change (refractive) |
| Depth-of-focus extension | Broader than standard LAL; comparable to or slightly greater than Eyhance | Modest (~0.50 D beyond a standard monofocal); less than Vivity |
| Adjustable after surgery? | Yes UV light adjusts sphere and cylinder | No |
| Contrast sensitivity data | Measured at 100% and 25% contrast in a registry; no independent testing | Equivalent to a standard monofocal; confirmed safe in glaucoma |
| Glaucoma-specific evidence | None | Three independent studies across glaucoma severity |
| UV eyewear compliance | Required ~2–3 weeks until lock-in | Not required |
| Independence of key data | All studies RxSight-sponsored | Mix of industry and independent academic work |
Chart 2. Light Adjustable Lens versus PureSee (EDOF)
| Feature | LAL | PureSee (EDOF) |
|---|---|---|
| Contrast sensitivity impact | None (monofocal) | Minimal (contrast comparable to a monofocal) |
| Visual field interference | None | Minimal (non-diffractive) |
| Refractive adjustability | Yes (±2.0 D post-op) | No |
| Toric version | Astigmatism corrected with light (nothing to rotate) | Yes, PureSee Toric II for ≥1 D — but a toric can rotate |
| Spectacle independence | Limited (monofocal or monovision) | Better intermediate range |
| Suitability for glaucoma | Favorable (monofocal optics) | Caution advised |
Chart 3. Lowest available powers and toric availability
| Lens | Power range | Toric option | Fit for this patient (~8–9 D) |
|---|---|---|---|
| Eyhance Toric II | +5.0 to +34.0 D | Yes | Within range |
| Light Adjustable Lens / LAL+ | −2.0 to +30.0 D | Astigmatism corrected with light | Fits with ample adjustment headroom |
| PureSee / PureSee Toric II | +5.0 to +34.0 D | Yes (Toric II, ≥1 D) | Fits, but toric can rotate + glaucoma caution |
My recommendation for this patient
First choice: the Light Adjustable Lens Plus (LAL+)
Her two best options are the LAL+ and the Eyhance Toric II, and I am recommending the LAL+. Her high myopia makes the final refraction hard to predict, and the LAL+ lets us correct it with light after the eye settles. She also has real astigmatism (1.70 D OD), and a toric lens loses about 3.3% of its correction for every degree it rotates. The LAL+ corrects astigmatism after healing with nothing to rotate, and the RxSight numbers confirm the light adjustment can flatten about 3.25 D and steepen about 4 D, more than enough to treat her entire cylinder. The lens also comes in exactly the low powers her long eyes need.
Why not PureSee for this patient
| Concern | Why it matters here |
|---|---|
| Astigmatism now correctable, but by a toric | A PureSee Toric II exists for her 1.70 D, but any toric can rotate and lose the correction, the exact problem the LAL+ avoids |
| EDOF optics in moderate-to-severe glaucoma | Any contrast trade-off adds to an already-compromised optic nerve |
| Greater depth of focus, greater miss sensitivity | Long eyes miss target more often, shifting the whole focus range, with no way to adjust afterward |
| No glaucoma-specific safety data | None at any severity |
| Pupil-dependent performance | Future glaucoma drops that shrink the pupil could degrade distance vision |
PureSee is an exciting, well-designed, non-diffractive lens, and it now has a toric version, but for this particular glaucomatous, very long eye the LAL+ remains the better fit.
If we did choose the Eyhance Toric II instead: the target plan
| Eye | Recommended target | Why |
|---|---|---|
| OD (first, non-dominant) | −0.25 to −0.50 D | Sits in the Eyhance sweet zone (distance sharp to ~−1.1 D), buffers the hyperopic shift, keeps the eyes close together for a glaucoma patient |
| OS (second, dominant) | Plano, adjusted after seeing the OD result | Optimizes distance; if OD drifts, OS can be nudged into gentle micro-monovision |
The bottom line for you, the patient
| Your situation | What we usually favor |
|---|---|
| Fine with glasses | Monofocal, excellent and covered by insurance |
| Drive at night, dislike halos | Avoid diffractive multifocals |
| Have astigmatism | Light Adjustable Lens, tuned after healing with nothing to rotate |
| Have glaucoma or macular disease | Monofocal, enhanced monofocal, or Light Adjustable Lens to protect contrast and clean visual fields |
| Very nearsighted | Confirm the lens comes in a low enough power, and plan for adjustment |
There is no perfect lens, only the best lens for your eyes, your life, and your night driving. That is the conversation I want to have with you in the office.
References
- Miller KM, et al. Cataract in the Adult Eye Preferred Practice Pattern. Ophthalmology. 2022;129(1):P1-P126.
- Zhu X, et al. Early Transient IOP Spike After Cataract Surgery in Highly Myopic Eyes. Br J Ophthalmol. 2020;104(8):1137-1141.
- Lidder AK, et al. IOP Spike Following Stand-Alone Phacoemulsification in the IRIS Registry. Ophthalmology. 2024;131(7):780-789.
- Laube T, et al. Pseudophakic Retinal Detachment in Young-Aged Patients. PLoS One. 2017;12(8):e0184187.
- Thylefors J, et al. Retinal Detachment After Cataract Surgery: A Population-Based Study. Acta Ophthalmol. 2022;100(8):e1595-e1599.
- Qureshi MH, Steel DHW. Retinal Detachment Following Cataract Phacoemulsification, a Review. Eye (Lond). 2020;34(4):616-631.
- Yao Y, et al. Efficacy and Complications of Cataract Surgery in High Myopia. J Cataract Refract Surg. 2021;47(11):1473-1480.
- Felipe A, et al. Residual Astigmatism Produced by Toric IOL Rotation. J Cataract Refract Surg. 2011;37(10):1895-1901; with Li ES, et al. 2024 rotational-stability data.
- Holladay JT, Haller M. Light-Adjustable Lens FDA Post-approval Study. J Cataract Refract Surg. 2026;52(7):666-669.
- Johnson & Johnson. FDA approval and U.S. availability of TECNIS PureSee IOL (ZEN00V) and PureSee Toric II. March–June 2026; power range +5.0 to +34.0 D.
- Alcon. Clareon PanOptix Pro U.S. introduction, 2025; power range +6.0 to +34.0 D.
- RxSight. LAL and LAL+ available power range −2.0 to +30.0 D (manufacturer, 2026).
This article is general educational information from Visionary Eye Doctors and is not a substitute for a personal examination. Every eye is different. Your surgeon will individualize your lens choice, targets, and risks to your specific measurements.
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.