I've noticed that cheap sunglasses (the kind sold for $5 to $10 by many supermarkets and drugstores) very often aren't optically correct; but I hadn't realized they could actually be hazardous to the health of your eyes. The Daily Mail reports on problems encountered with them in England - but since the cheap sunglasses sold in the USA come from the same source (mostly Chinese factories), the dangers are the same on this side of the Atlantic.
Cheap sunglasses may look like a bargain, but could leave you seeing double or developing headaches.
Even those costing £5 from high street names such as Tesco and M&S failed some lab tests, breaching British Standard quality markers, according to consumer group Which?
It tested three pairs of sunglasses bought from each of seven stores – Asda, M&S, New Look, Poundland, Primark, Sainsbury’s and Tesco – all costing between £1 and £5.
Fifteen pairs failed key tests and only the three from New Look passed everything.
All three pairs from Poundland had what opticians call a vertical prism in the lenses.
Present in some prescription glasses, it has the effect of bending light and can cause double vision or headaches in some wearers.
One pair was labelled good for driving when the lenses were too dark for such use.
A £1 pair from Primark had lenses containing optical power – in other words acting like prescription lenses – and each lens let in different amounts of light.
The Primark glasses could make vision problems such as astigmatism worse, said Which?
A pair of £5 sunglasses from Tesco and one from Asda had one lens different to the other, while several sunglasses let in different amounts of light in each lens.
. . .
Of 40 branches of chains and some small independents visited, a third were judged not up to scratch.
There's more at the link.
I guess I won't be buying any more cheap sunglasses. My desire for ongoing optical health makes it worthwhile to invest in something better.