It has been confirmed that the monarch underwent eye surgery to remove a cataract in May, and has been wearing shades as it can take four to six weeks to recover from the routine operation.
"I can confirm that the Queen successfully underwent a short planned procedure to treat a cataract last month", the spokesperson said.
Queen Elizabeth II donned sunglasses at a garden party at Buckingham Palace on May 31.
Cataracts occur when the lens, a small transparent disc inside the eye, develops cloudy patches, over time growing and causing blurry, misted vision and even blindness if left untreated.
Queen of great Britain, 92-year-old Elizabeth II has had surgery on his eyes.
Image Her Majesty attending the opening of The Queen's Diamond Jubilee Galleries at Westminster Abbey on Friday
A cataract is a clouding of the lens in the eye, leading to a decrease in vision.
The Queen was treated at the King Edward VII hospital in central London - the same hospital which carried out the hip replacement operation on her husband, the Duke of Edinburgh, in early April.
The surgery is performed under local anesthetic and is usually over within 40 minutes.
In 2013, she had her first hospital stay in 10 years when, at the age of 86, she suffered symptoms of gastroenteritis and missed an engagement in Swansea. During recovery, patients have to protect their eyes from bright light for at least a few weeks.
The queen and the duchess are scheduled to travel north overnight on Wednesday in the Royal Train to Cheshire, where they will open a new bridge, visit a theater and have lunch at the Chester Town Hall.