Can the cheap sunglasses have good UV protection?

[Herbster]

I just bought some really cool sunglasses for only $5 from a discount store.I saw there was a sticker a sticker saying "UV Protection Factor 400",but I wonder can they provide that level of protection, at that price?

[Herculaneum]

Here's a useful tip to tell if the sunglasses have UV protection or not. Look at an monocromatic LCD screen (the digital screen at a gas pump, or an LCD wristwatch for example) thru the lenses. You will probably see on first glance that the screen looks flat black (where are the numbers?) but as you tilt/rotate your head slightly (so one eye is higher than the other) you will see the display change. This is due to the interaction between the filter pattern in the glasses and the LCD screen.

[Hercules]

$5? R U KIDDING? I don't believe such cheap sunglasses can prevent UV ray.

[Herd]

If you want to ensure the UV protection of your sunglasses, you'd better purchase them from reputable companies, specialty sunglass stores or from an optical professional.

[Hereford]

General speaking, the sunglasses contain UV protection more or less unless you get them from a stall in the middle of the street. As you get them from a discount store, i think you don't need to worry about it.

[Herington]

They may block the UV rays more or less but can't provide the level of protection as it claims on the sticker.For 100% UV protection,you'd better buy them at a reliable store.