Cataract Surgery
The eye’s natural lens can gradually become cloudy over time, a change known as a cataract. This clouding often develops slowly enough that it’s easy to miss at first: colours may start to look faded, night driving becomes harder because of glare from oncoming headlights, more light is needed to read comfortably, or a glasses prescription keeps changing every year or two without ever quite settling.
Cataract extraction is the procedure that treats this. The clouded natural lens is removed and replaced with an artificial intraocular lens that provides the focusing power needed after the natural lens has been removed. Beyond restoring clarity, the specific type of IOL chosen can also affect how dependent a patient remains on glasses afterwards, which is covered separately below.
What Is Cataract Surgery Used to Treat?
Cataract surgery treats vision affected by a cataract (clouding of the eye’s natural lens), which can cause blurred or hazy vision, glare around lights, faded colour perception and difficulty seeing clearly in low-light conditions.
The Cataract Surgery Procedure
The procedure is most commonly performed using phacoemulsification, a technique in which a small incision is made at the edge of the cornea (the clear, dome-shaped surface at the front of the eye), and an ultrasonic probe breaks up the clouded lens so it can be gently removed. Femtosecond laser assistance (an ultra-short-pulse laser) may be used for certain steps of the procedure, such as opening the front lens capsule, dividing the lens or creating the initial incision, depending on the individual case. Once the natural lens is removed, the artificial intraocular lens (IOL) is folded and inserted through the same small incision, where it unfolds and settles into position.
In Plain Terms: The cloudy lens inside the eye is broken up using ultrasound energy and removed through a very small opening. It is then replaced with a clear artificial lens that remains permanently inside the eye. The surgical portion is generally brief, usually taking under half an hour.
Who May Be Suitable for Cataract Surgery?
Patients with a cataract that is affecting everyday activities such as reading, driving or recognising faces may be considered for surgery. The decision is based on the extent to which the cataract is affecting vision and daily life, together with the overall health of the eye.
Recovery and Expected Results
Many patients notice clearer vision within a few days, with most improvement occurring during the first week and vision continuing to stabilise over approximately 4 to 6 weeks. Temporary light sensitivity, mild scratchiness or watering is common during the early healing period. Recovery may take longer in patients with other eye conditions, such as corneal disease or retinal problems, which may require closer monitoring during healing.
Choosing an Intraocular Lens
Cataract surgery involves replacing the clouded natural lens with an IOL. Which lens type is most suitable depends on an individual assessment of the patient’s eyes and visual needs.
Monofocal Lenses
A monofocal lens focuses light clearly at one main distance, most commonly for distance vision. Reading glasses are therefore typically still needed for near tasks. It is possible to insert a distance lens in one eye and reading lens in the other eye in a strategy called monovision. These lenses generally provide high-contrast vision with a lower likelihood of glare or haloes around lights compared with multifocal lenses.
Toric Lenses
A toric lens is designed to correct astigmatism (a refractive error caused by differences in the shape of the cornea or lens, producing blurred or distorted vision) at the same time as treating the cataract. Toric lenses are available in both monofocal and multifocal designs.
Multifocal & Extended Depth-of-Focus (EDOF) Lenses
These lenses are designed to provide useful vision across more than one distance, including near, intermediate and far, with the aim of reducing dependence on glasses. The trade-off can include a greater likelihood of glare or haloes around lights, particularly at night, as well as a period of neuroadaptation (the time the brain takes to adjust to processing the different visual information provided by the lens).
EDOF lenses are designed to extend the range of focus beyond that of a standard monofocal lens, though how much range is gained and whether visual disturbances occur depend on the specific lens design and the individual eye.
Who May Be Suitable for a Multifocal or EDOF Lens?
Suitability depends on the health of the cornea, retina and other structures of the eye, as well as the patient’s visual priorities. Patients who place a high value on reducing their dependence on glasses may consider a multifocal or EDOF lens, while others may prioritise contrast and night vision quality. Not every eye is suitable for a premium lens, so the decision is based on the individual assessment rather than preference alone.
Potential Risks and Limitations
As with any intraocular procedure, cataract surgery involves potential risks and limitations. These may include infection, inflammation, bleeding, increased eye pressure, swelling of the cornea or retina, retinal detachment, an unexpected refractive result, posterior capsule opacification and the need for additional treatment or surgery. In rare cases, complications may cause permanent loss of vision. The risks relevant to each patient are discussed during consultation and as part of the informed consent process.
Why an Accurate Assessment Matters
A premium multifocal or EDOF lens chosen without first assessing retinal health, corneal shape and other aspects of eye health may result in glare, haloes or reduced contrast at night that outweigh the benefit of reduced glasses dependence. In some eyes, particularly those with certain corneal irregularities or retinal conditions, a premium lens may not be advisable even when a patient would prefer one.
Dr David Robinson has performed more than 3,300 cataract procedures over more than 28 years of surgical experience. During your assessment, he considers the health and structure of your eyes alongside your visual priorities, explaining which lens options are appropriate, the advantages and limitations of each, and what you can reasonably expect from your chosen lens. This allows the decision to be based on your individual eyes and priorities rather than on a standard lens choice.
Common Questions Patients Ask
Is cataract surgery painful?
Cataract surgery is generally performed under local anaesthetic. There is generally no pain felt during the operation. Patients may notice pressure, or glare during the procedure, and some discomfort during recovery is common. Individual experiences vary.
How long does the procedure take?
The surgical portion is typically under 30 minutes per eye, although the full visit takes longer because it includes preparation, dilation and post-operative monitoring.
When can a patient drive again?
This is assessed individually at the first follow-up appointment, often the day after surgery, and then again one week after surgery when vision usually meets the legal standard required for driving. Driving should not be assumed to be safe immediately after surgery.
Will a cataract return after surgery?
No. The artificial lens cannot develop a cataract. However, the thin membrane behind the artificial lens can become cloudy in some patients months or years later. This is known as posterior capsule opacification (clouding of the membrane that holds the lens in place) and can usually be treated with a separate laser procedure.
Will vision be completely glasses-free after surgery?
This depends on the type of lens selected and the individual characteristics of the eye. A monofocal lens generally means glasses are still needed for some distances, while multifocal or EDOF lenses may reduce dependence on glasses without guaranteeing complete freedom from them.