ISBCS (immediate sequential bilateral cataract surgery) means both of your cataracts are removed in the same sitting, as two completely separate sterile procedures with fresh instruments, gowns and intraocular lenses for each eye. At our partner clinics, same-session bilateral surgery starts from £5,500 for both eyes with monofocal lenses, £7,200 for EDOF and £8,200 for multifocal IOLs, all-inclusive. ISBCS suits motivated, otherwise healthy patients with cataracts in both eyes who want balanced vision and a single recovery rather than two separate operations weeks apart.
What is ISBCS?
Traditionally, cataract surgery is done one eye at a time, with the second eye operated a few weeks later — a pathway called delayed sequential bilateral cataract surgery (DSBCS). ISBCS compresses that into a single visit: the first eye is completed in full, the theatre is reset as if for a brand-new patient, and the second eye is then treated as an independent operation. The two eyes never share instruments, fluids or lens implants, which is what keeps the infection risk for each eye effectively the same as a standalone operation.
ISBCS has grown rapidly across Scandinavia, Canada and increasingly the UK because the outcomes match staged surgery while sparing patients a second admission, a second anaesthetic episode and weeks of imbalance between a treated and an untreated eye. For the right patient it is faster, more convenient and avoids the awkward in-between period where the two eyes are very different. Learn more about the operation itself on our main cataract surgery page.
Benefits of same-session surgery
- One recovery, not two — a single course of drops, one set of activity restrictions, one period off driving
- Balanced vision quickly — no weeks of imbalance between an operated and an unoperated eye
- Fewer hospital visits — one admission and one shared set of pre-op checks
- Faster return to life — ideal for working patients and those who travel to the clinic from a distance
- Lower overall cost — a single theatre session usually costs less than two separate visits
- Single anaesthetic episode — helpful for frail patients for whom repeated visits are harder
Cataracts in both eyes? A consultant assessment with biometry will confirm whether ISBCS is the safest, most convenient route for you.
Book a cataract assessmentISBCS vs staged surgery vs lens choice
Two decisions sit side by side: whether to have both eyes in one session, and which intraocular lens to choose. Your consultant guides both, based on your eye anatomy, your general health and your lifestyle goals.
Because both lenses are chosen and implanted on the same day, ISBCS is particularly well suited to patients who want a matched pair of premium lenses for balanced near, intermediate and distance vision. If you are exploring a fuller move away from glasses, your surgeon may also discuss refractive lens exchange and the wider range of implant lens options.
What happens on the day
ISBCS is performed under local anaesthetic eye drops. You stay awake and feel no pain — only mild pressure and light. Each eye takes around 15 to 25 minutes, and you are at the clinic for roughly half a day including pre-op checks, both procedures and post-op rest.
- The first eye is prepared, draped and operated in full: a 2.2–2.8mm self-sealing incision, phacoemulsification to remove the cloudy lens, and implantation of your chosen IOL.
- The theatre is completely reset — new sterile instruments, fluids, gowns, drapes and a separately sourced lens implant, exactly as for a new patient.
- The second eye is then treated as an entirely independent sterile operation using a different batch of consumables.
- Separate antibiotic precautions are used for each eye to keep the risk profile of each procedure standalone.
- You rest for a short period and go home the same day with a single set of drops and instructions.
Recovery week-by-week
With ISBCS there is one recovery rather than two. Most patients notice clearer vision in both eyes within hours, with full settling over about a month. Our recovery timeline guide covers this in more detail.
Day of surgery
Vision is hazy in both eyes for a few hours. Shields worn for the first night. No driving, no heavy lifting. Eye drops begin in both eyes.
Days 1–3
Vision begins to clear in both eyes together. Mild grittiness or watering is normal. Most return to gentle activities and reading.
Week 1
First post-op review. Many patients are back to driving and work with balanced vision — no swimming or eye rubbing yet.
Weeks 2–4
Vision continues to refine in both eyes. Drops continue. New glasses prescription, if needed, at week 4–6.
Beyond a month
Final balanced vision is settled. Most patients describe clarity they have not had in years, in both eyes at once.
Cost & insurance
ISBCS pricing is all-inclusive and covers consultation, biometry, both operations, theatre and hospital fees, both IOLs of your choice, post-op drops and your follow-up reviews. Because both eyes share a single theatre session and one set of pre-op checks, same-session surgery usually costs less than two separate visits.
- Self-pay: from £5,500 both eyes (monofocal); £7,200 EDOF; £8,200 multifocal. Toric lenses for astigmatism add from £500 per eye.
- Insurance: recognised by Bupa, AXA, Aviva, Vitality, Cigna, WPA and others. We handle authorisation — see insured patients.
- Finance: 0% options available — see our finance page. Full per-lens pricing is on the cataract surgery price list.