Cataract
Cataract: when to operate and how to choose the lens
Cataract surgery is one of the most common and safest operations in medicine. The big decision is usually not whether to have it, but when and with which lens.
By Dr Idaira Sánchez Santos, ophthalmologist · Nº 390905425
Last reviewed: · Patient information. It does not replace a medical consultation.
What a cataract is
The crystalline lens is the eye's natural lens. With age it becomes cloudy and yellowish: that is a cataract. It shows as blurred or hazy vision, glare when driving at night, faded colours or frequent changes in your glasses prescription.
When to have surgery
There is no longer any need to wait for a cataract to "ripen". The usual advice is to operate when it starts to limit your daily life: driving, reading, working or moving around safely. It may also be brought forward for other medical reasons your ophthalmologist will assess.
What the operation involves
It is done by phacoemulsification: through an incision of about 2 mm the lens is broken up and removed and a foldable intraocular lens is implanted. It is a day-case procedure with anaesthetic drops and light sedation, and usually takes about 15 to 20 minutes per eye.
Which intraocular lens to choose
- Monofocal: excellent quality of vision at one distance (usually far). You will need reading glasses.
- Toric: also corrects astigmatism.
- Multifocal or trifocal: distance, intermediate and near, with less need for glasses. They can cause halos at night and are not suitable for every eye.
- EDOF (extended depth of focus): good distance and intermediate (computer) vision, with fewer halos than multifocals.
The right lens depends on your measurements (biometry), your cornea, the health of your macula and your daily activities.
When an online consultation helps
- You have been offered surgery and want a second opinion on timing or lens type.
- You are unsure between a monofocal, toric, multifocal or EDOF lens.
- You live abroad and want to consider having surgery in Santander, Spain, before travelling.
- You have already had surgery and have blurred vision, halos or questions about recovery.
Which tests to send the doctor
- Biometry (IOLMaster, Lenstar or similar)
- Corneal topography
- Macular OCT
- Current glasses prescription and visual acuity
- Any report or quote you have been given
In the days after cataract surgery, increasing pain, a redder and redder eye or loss of vision need same-day in-person assessment.
Frequently asked questions
Can a cataract come back?
No, because the natural lens is removed. But the capsule that holds the new lens sometimes becomes cloudy over time; this is fixed with a quick laser in clinic (YAG capsulotomy).
Can both eyes be done on the same day?
Usually one eye is operated and the second days or weeks later. Some centres offer same-day surgery for both eyes in selected cases; it is decided with each patient.
Can I have surgery in Santander if I live in another country?
Yes. The online consultation is used to review your tests and plan the trip and the number of in-person visits needed before and after surgery.