Intraocular lens (IOL) options
Most cataract surgery decisions reduce to how you want to manage focus at different distances: distance, intermediate (computer), and near (reading).
1) Monofocal (standard)
One crisp focal distance per eye (usually distance). Near tasks typically need reading glasses.
- Strength Highest predictability and often best contrast sensitivity.
- Strength Usually least night‑vision disturbance from lens optics.
- Trade‑off Glasses for reading and sometimes intermediate work.
2) Toric monofocal
Monofocal lens with astigmatism correction built in. Intended to reduce blur from corneal astigmatism.
- Strength Can improve uncorrected distance vision if astigmatism is significant.
- Trade‑off Still a single focal distance (readers still likely).
- Consider Needs precise alignment; rotation can reduce effectiveness.
3) Extended depth of focus (EDOF)
Optical design aims to stretch focus to give a broader “in‑between” range (often better for computer and general tasks).
- Strength More usable intermediate range than monofocal.
- Trade‑off Near reading may still need glasses, especially small print.
- Risk Some people notice haloes/glare or reduced contrast in dim light.
4) Multifocal / trifocal
Splits light into multiple focal points to cover distance + intermediate + near, aiming for reduced glasses dependence.
- Strength Greater chance of being less dependent on glasses across distances.
- Downside Higher chance of haloes, glare/starbursts, and lower contrast (especially at night).
- Reality Satisfaction depends heavily on expectations, lifestyle, and ocular surface health.
5) Monovision / mini‑monovision targets
Uses lens power targeting rather than a different lens design: one eye is set for distance, the other slightly nearsighted for near work.
- Strength Can reduce readers without multifocal optics.
- Trade‑off Some loss of binocular balance (depth perception, comfort).
- Key point Tolerance is highly individual; “try before you commit” helps.
6) Newer / specialised designs
Technology evolves (e.g., different EDOF profiles, small‑aperture designs, accommodating concepts). Availability varies by region and surgeon.
- Practical Ask what your surgeon uses regularly and why.
- Practical Ask about your suitability: dry eye, macular issues, corneal irregularity, night driving needs.
- Practical Ask about enhancement paths: laser touch‑ups, IOL exchange, or glasses.
What often matters more than the lens label
Ocular surface (dry eye)
Dry eye can cause fluctuating blur, glare, and poor measurements. Optimising the surface before biometry improves outcomes.
Astigmatism management
Small residual astigmatism can undermine any lens choice. Toric IOLs or corneal incisions may be used.
Expectation calibration
“Glasses‑free” is not guaranteed. Decide what you can accept: occasional readers, night artefacts, or a bit less crisp contrast.