High street sunglasses fail British standards

Which? tested 21 pairs of sunglasses from seven high street shops and found that 15 failed key lab tests, breaching the British Standard.

You might not expect a pair of £5 sunglasses to last forever, but you wouldn't expect a supposed bargain to potentially worsen your eyesight, cause double vision or headaches.

Too dark for driving

The sunglasses on test were bought from George at Asda, Marks & Spencer, New Look, Poundland, Primark, Sainsbury's and Tesco.

All the sunglasses blocked UV rays, but a Poundland pair was mislabelled, leaving a wearer unaware that the lenses were too dark for safe driving.

Although two out of three Primark pairs passed our tests, the one that failed had the wrong prescription level which could make vision problems, such as astigmatism, worse.

Flying colours for NewLook

New Look was the only store where all three pairs passed the Which? tests with flying colours.

Which? health expert Joanna Pearl said: 'While these problems would not cause long-term vision damage, some of them would be unpleasant for the wearer and could even compromise their safety. Glasses must comply with the British Standard they clearly claim to meet on the label.'

Stores to investigate Which? findings

We will be sending the worst results to Trading Standards.Asda, M&S, Primark, Sainsbury's and Tesco all confirmed that their sunglasses are tested to British Standards.

M&S, Primark, Sainsbury's and Tesco rigorously disputed Which?'s findings, with M&S expressing their surprise and disappointment.

Asda, Poundland and Primark will be investigating immediately.

Tips for buying sunglasses

If you're buying sunglasses make sure you do the following checks:

• Check for the CE Mark and the British Standard BS EN 1836:2005 for adequate protection against the sun's UV rays.
• Check the filter category of the glasses (how dark they are) from 1 to 4: category 4 is the darkest and not suitable for driving.
• Remember that you are buying a pair of glasses. Before buying hold the glasses at arm's length and look at a window edge through one lens then the other, looking up and down to make sure the image is clear.
• Check for scratches as they can distort your vision.
• Manufacturers tend to make sunglasses in three sizes, so try them on to make sure they fit.
• Tinted lenses in colours such as red and orange can distort colours when you're driving; grey lenses are best for avoiding this, and brown ones are ok too.

Here are our results for each pair we tested and the standards they failed on: