The UK CAA require a period of at least six weeks after cataract surgery. You will need to inform them of the date of the surgery and your medical will be suspended from that date (therefore the privileges of your licence will be suspended).
They require you to be formally signed off by the consultant after follow up appointments and you will subsequently require another CAA medical, obviously the eye test being the critical issue.
After it's been done, you will be amazed how much your sight had deteriorated.
The CAA have more info on their website.