20 metres, 6/12: when can you drive after cataract surgery

The short answer to "can you drive after cataract surgery" is: not on the day of the operation, and only once your eyes together meet the legal standard where you drive, which in the UK means reading a number plate from 20 metres and a visual acuity of at least 6/12. Most people need someone else behind the wheel for the first trips, because the operated eye is still settling and the other eye may not match it yet. If you're flying home after surgery in Seoul, the worry is practical: who drives you from the airport, and who confirms your eyes meet that standard before you drive alone again.

I'm Dr. Kim Sun-young, Medical Director of Healing Eye Clinic in Gangnam, with a specialty in cornea, glaucoma and cataract, and I've written this for people planning cataract surgery in Seoul with a car waiting for them at home.

At Healing Eye, one surgeon owns your care from the first exam through surgery to aftercare, so the person you ask "when can I drive?" is the same person who measured your eyes before the operation.

The most useful thing to send before you book is small: a photo of your latest glasses prescription or eye report, plus the date you need to be driving again at home.

What eyesight does the driving standard actually ask for?

In the UK, GOV.UK sets three conditions for car drivers: you can read a number plate from 20 metres, your visual acuity is at least decimal 0.5 (6/12) on the Snellen scale with glasses or contacts if you need them, and your field of vision is adequate. The acuity is measured with both eyes together.

On the eye charts most American readers know, 6/12 is written as 20/40. Licensing rules in the US, Canada and Australia are set by their own authorities, so check the wording from your own licensing office before assuming the UK numbers apply to you.

Two details in the UK wording matter after cataract surgery. If you need glasses or contact lenses to meet the standard, you must wear them every time you drive. A cataract treated one eye at a time is exactly the situation where people are unsure which rule applies, and GOV.UK sends you to its A to Z of medical conditions for that, so read the entry for your own case.

The numbers on your post-op check that decide the first drive

Four measurements decide it: the sharpness of the operated eye, the sharpness of both eyes open together, the prescription still left in each eye, and how much glare you notice from lights. If you also have glaucoma or another condition affecting side vision, a field-of-vision test belongs on that list as well.

A first post-op result can be misleading on its own. An operated eye that reads 6/9 without glasses sounds like a green light, but if the other eye still has a dense cataract and a strong prescription, the two eyes together can perform worse than the good eye alone, because the brain is trying to merge two very different images. That is why the both-eyes number, measured with whatever you will actually wear in the car, is the one that counts.

Why is the gap between the two eyes the hardest stretch for strong prescriptions?

If you were very short-sighted, the first operated eye may now need little or no distance correction while the other eye still needs a strong lens. Your old glasses then fit one eye and fight the other. That mismatch, called anisometropia, is a common reason people stay off the road between the first and second surgery.

There are a few ways around it, and each has a cost. A contact lens in the unoperated eye works well if you already tolerate contacts. A temporary pair of glasses with the lens on the operated side changed can help, though some people still find the difference in image size tiring. A shorter interval between the two operations removes the gap, but it means a longer stay or a second trip planned in advance.

Which of these suits you depends on how dense the second cataract is, your history with contact lenses, and how many days you can be in Seoul. The trade-offs of treating one eye or both on the same Seoul stay are worth reading before you choose.

Night driving, glare and halos in the first weeks

Daytime driving often comes back before night driving. The American Academy of Ophthalmology lists halos and glare among the possible problems after cataract surgery, and in the first weeks they can come from the healing eye, from the cataract still in the other eye, or from the optics of the new lens.

Some people notice rings around headlights with them, and for a minority those rings stay noticeable. If you drive a lot after dark, that is a real reason to look closely at a monofocal lens set for distance, and it is a conversation to have before the lens is chosen.

If someone in your family reads Korean, the clinic's Korean page on premium intraocular lenses is a good thing to pass on to them before the consultation.

Which symptoms after you fly home mean stop driving and call?

Stop driving and get your eye seen promptly for any of the warning signs the National Eye Institute lists: vision loss, severe pain that medicine doesn't relieve, very red eyes, or floaters. Treat flashes of light or a shadow spreading across your vision the same way, since retinal detachment is a recognised complication.

Risks and side effects to know

Like any operation, cataract surgery carries risks. The AAO lists infection, bleeding, retinal detachment, blurred vision, halos or glare, vision loss and dislocation of the lens implant, and the NEI adds swelling and unusual changes in eye pressure. The NEI also notes that a secondary cataract, the capsule clouding in the last row of the table, can appear weeks, months or even years after surgery, and that it is treated with a laser.

How quickly vision settles varies from person to person, and whether surgery suits your eyes at all is decided at the in-person exam.

The approach in our guide to aftercare once you're back home was written for laser surgery, but its logic about who to contact first carries over to cataract surgery.

If one of these situations is already on your mind, put it in a single line, for example "my right eye is minus 9 and I drive to work every day", and send it on WhatsApp with a photo of your prescription. We reply in English, and that line is a good place to start the consultation from.

What your eye doctor at home will want to see

Bring a short file home: the operation date for each eye, the lens model and power implanted, your last measured acuity and prescription, the drop schedule, and a note about the second eye if it hasn't been done. With those in hand, a local optometrist or ophthalmologist can check you against the driving standard in a single visit.

Ask for those details while you're still in Gangnam. What usually happens day by day is set out in the realistic recovery timeline, and what vision tends to look like in the first days has its own brief for patients flying in.

How long should you plan before the first drive on your own roads?

Plan on no driving on surgery day and on someone else driving you home from the airport. Many people see better within a few days, but the AAO puts full healing at about 4 to 6 weeks and the NEI says most people are completely healed by 8 weeks, so your first solo drive should follow an eye check, not a date on the calendar.

How many nights you spend in Seoul is confirmed at the consultation, and the trade-offs are laid out in how long to stay in Korea for cataract surgery. Getting around Seoul without a car is the easy part: the clinic is one minute's walk from Sinnonhyeon Station, the partner hotel is O'Cloud Hotel in Seocho-gu, and the NEI is clear that you won't be able to drive straight after the operation anyway.

If you're organising this for a parent who still drives, the companion's guide for families is written for the role you'll play.

Before you book a flight, send one photo on WhatsApp: your current glasses prescription or most recent eye report, with a line on how often you drive and the date you need to be back behind the wheel. We reply in English, and that date is the first thing worth raising when your surgery days are planned.