The 92-year-old Queen underwent the delicate procedure at the private King Edward VII's hospital in London, where she was treated as a day patient.
The planned operation resulted in a success, as confirmed by a source familiar with the event.
A Buckingham Palace spokesman said: "I can confirm that the Queen successfully underwent a short planned procedure to treat a cataract last month."
In recent weeks the Queen has been sporting a pair of sunglasses at a number of events, including the Royal Windsor Horse Show and Buckingham Palace garden parties.
It is unclear weather this fashion choice is related to the operation.
Cataracts are an eye conditions happening when the lens, a small transparent disc inside the eye, develops cloudy patches.
Over time these patches usually become bigger causing blurry, misty vision and eventually blindness, if left untreated. Read more from EXPRESS.