Parents are being warned about unsafe and illegal sunglasses sold online that could damage children's eyesight. A Which? investigation found that children’s sunglasses sold on some of the most popular marketplaces, including Amazon and eBay, failed safety tests and are illegal to sell in the UK.

None of the 20 pairs purchased from six online marketplaces should be sold legally in the UK, as they were all missing key information, labels and markings, such as CE or UK Conformity Assessed markings (UKCA). UV protection levels were found to be dangerously low in two of the pairs tested, despite claiming to have full UV protection, which is also illegal in the UK. Some offered significantly different protection from one lens to the other.

The sunglasses were purchased from Amazon, AliExpress, eBay, TikTok, Temu and Shein, and several models used novelty shapes which may appeal to children, such as heart or cat-shaped lenses.

Among the illegal sunglasses were the Cute Cat Kids’ Sunglasses UV Protection on Amazon, Classic Vintage Holiday Sunglasses UV400 on eBay, Kids’ Aviators from AliExpress, £1 Kids Sunglasses from Temu and Red heart-shaped sunglasses from eBay.

These models either made misleading claims about their ability to block UV rays or had inconsistent UV filtering.

Which? has labelled all sunglasses as 'Don’t Buys' and has urged consumers to avoid them, especially if they appear to be unbranded. It said compliance with safety rules is much more stringent in high street stores.

Overexposure to UV over time can lead to cataracts and macular degeneration. Children are particularly vulnerable to UV light as their eyes are still developing.

Which? has called for tough new laws to make online marketplaces take responsibility for the products they sell on their sites.

Rocio Concha, Which? Director of Policy and Advocacy, said: “Our research shows many of these models are so ineffective as to be dangerous for children to wear and this is a consequence of online marketplaces having no real responsibility or incentive for taking safety seriously.

“The government’s Product Regulation and Metrology Bill must be strengthened to include legal responsibilities for online marketplaces to ensure the products they sell on their sites are safe, with heavy fines for those that fall short of the required standards.”

All marketplaces said they have strict policies in place to ensure product safety, and that all vendors must comply with their regulations.

A spokesperson for Amazon said: "We continuously monitor our store and take action to maintain a safe selection for our customers, including removing noncompliant products and reaching out to sellers, manufacturers, and government agencies for additional information. The products in question have been removed."

AliExpress told Which? it had removed the items that failed the tests. A spokesperson added that while it conducts random inspections on physical products and takes action against the merchants selling non-compliant products, it may not be able to verify the compliance of all the products.

eBay has removed the sunglasses. A spokesperson said: "We proactively keep our site safe and prevent prohibited listings through seller compliance audits, block filter algorithms for unsafe listings, and AI-supported monitoring by our team of in-house specialists."

A spokesperson for Temu said: "All three flagged listings have been removed from the platform pending further review. As a precaution, we expanded screening of similar products to ensure full compliance with UK safety regulations."

A spokesperson for TikTok said: "The safety of our customers is of our utmost priority, and we have strict measures in place to ensure that our sellers comply with regulations and safety standards. These listings have been removed from our platform."

A spokesperson for Shein said: "We take product safety very seriously and are committed to offering safe and reliable products to its customers. We immediately removed the items from our site as a precaution while we investigate."