A warning has been issued to anyone wearing sunglasses as this spell of hot weather continues across the UK.

After a warm and sunny weekend, Brits have been out soaking up the sunshine in parks, beaches and countryside trails (as well as pub gardens).

And according to the Met Office, we're in for another sunny week, with temperatures expected to soar to as high as 23C on Friday, May 1.

But if you’re reaching for a pair of shades, experts are warning that your cheap sunnies need to be properly certified - or it could end up wrecking your eyesight.

Alex Day, a consultant ophthalmologist at Moorfields eye hospital, told the Guardian: “When you buy fake sunglasses, you are gambling with your sight. Counterfeit eyewear is uniquely dangerous because it usually features dark-tinted lenses with absolutely zero UV protection. From a medical perspective, wearing them is actually significantly worse than wearing no sunglasses at all.”

The College of Optometrists explains how sunshine can damage your eyes and tells households the exact certifications they should be looking out for which will be printed on the glasses on a sticker, or detailed in its packaging - BS EN ISO 12312-1:2013.

It says: “Bright sunshine is not only dazzling, it can also cause long term damage to your eyes. Sunglasses protect you from glare and also from harmful ultraviolet light, which can cause cataracts and may be linked to macular degeneration. Children are vulnerable to UV because they have larger pupils and clearer lenses in their eyes.

“When purchasing sunglasses, look for ones that have the “CE” Mark or British Standard BS EN ISO 12312-1:2013, which ensures that the sunglasses offer a safe level of UV protection.

A common misconception about sunglasses is that the darker the lens, the more protection they offer. There are a variety of tints available for sunglasses, so you can choose one to suit you. If you are out in the sun for long periods, you may want to consider wraparound sunglasses for greater protection. And don’t forget – a wide-brimmed hat offers great protection, too!”