Why post-LASIK cataract surgery is different
LASIK reshapes the front surface of the cornea to correct your prescription. That change stays with you for life — including into the era when you develop cataracts. Two things become more complicated:
- The maths for choosing the IOL power is built on assumptions LASIK broke. Standard formulas underestimate the power needed and typically leave patients half a dioptre or more longsighted.
- Optical quality is subtly reduced — LASIK corneas have slightly higher spherical aberration and lower contrast, which affects how well certain premium lenses perform.
How the IOL power is calculated
Post-LASIK-specific formulas
Barrett True-K, Haigis-L, and the ASCRS post-refractive online calculator are used together — not one formula in isolation. The results are cross-checked and the most conservative estimate usually chosen.
Intraoperative aberrometry
In selected cases the eye is measured again during surgery, once the cataract is removed and before the IOL is placed. This gives a real-time refractive check and can reduce post-LASIK refractive surprise further.
Realistic accuracy
In experienced hands, around 80–90% of post-LASIK eyes end up within 0.5 D of target — good but not quite as tight as unoperated eyes (around 95%). A written plan for what happens if there is a refractive miss is part of the pre-op discussion.
Choosing an IOL after LASIK
The safest and most predictable lens after LASIK is a good-quality monofocal or aspheric neutral monofocal — aiming for distance in the dominant eye and mini-monovision in the other if reading independence matters. EDOF lenses can work well in eyes with a smooth, regular LASIK cornea. Trifocal and multifocal lenses are usually avoided because glare and halo symptoms tend to be more noticeable in LASIK eyes.
See the premium lens selection guide for a full comparison.
Frequently asked questions
Can I have cataract surgery if I've had LASIK?
Yes — previous LASIK, PRK or SMILE does not stop you having cataract surgery. It changes how the intraocular lens power is calculated and which lens types are appropriate, but the surgery itself is essentially the same procedure.
Why is IOL calculation harder after LASIK?
Standard biometry formulas assume a normal relationship between the front and back curves of the cornea. LASIK reshapes only the front surface, so those assumptions no longer hold — using a standard formula typically leaves patients longsighted after cataract surgery. Post-LASIK-specific formulas (Barrett True-K, Haigis-L, ASCRS calculator) correct for this.
Should I have a multifocal lens after LASIK?
Usually not. LASIK slightly reduces contrast and can leave subtle higher-order aberrations. Adding a multifocal lens on top often causes noticeable glare and halos. Most post-LASIK patients do best with a monofocal or EDOF lens; a small subgroup with pristine corneas can be considered for multifocals case-by-case.
Will I need glasses after cataract surgery post-LASIK?
The refractive target is chosen with you. Most patients aim for good distance vision with reading glasses. Mini-monovision (one eye slightly under-corrected) is a popular option to reduce reading-glasses dependence without the compromises of a multifocal.
What if my LASIK records are lost?
Modern post-LASIK IOL formulas do not require your original pre-LASIK measurements — Barrett True-K without history and the Haigis-L formula work from current corneal data alone. Bringing old records is helpful but not essential.
Is there a higher risk of needing an IOL exchange?
Refractive surprise is more common after LASIK than in virgin eyes — around 5–10% of patients end up more than 0.5 D from target versus 1–2% in unoperated eyes. Options if this happens include a laser touch-up on the LASIK flap, a piggyback IOL, or an IOL exchange.
Post-LASIK cataract assessment
Advanced biometry, multiple formula cross-checks and a lens plan tailored to your corneal history.