Spending a small fortune on eyewear is no longer solely the domain of Hollywood starlets, with style-conscious Kiwis splashing out hundreds, even thousands, on the latest designer shades.

But if it's sun protection rather than fashion kudos you're after this summer, go ahead and buy those petrol station cheapies: they are probably just as good. Eye health experts told the Herald on Sunday that inexpensive lenses offered sun protection equal to, and in some cases greater than, shades costing 10 or 20 times the price.

The Consumer's Institute tested a dozen pairs of cheap lenses. With an average price of $13, all offered 99 per cent UV protection, despite some of the cheapies having no brand name or consumer safety labelling.

Wilson Sue, vice-president of the Optometrist Association, said a $20 pair of snug wraparounds from a chemist were likely to be safer than a pair of funky Miu Miu's with graduated lenses worth $400. "Graduated tints don't block the reflected light from the road surface or ground."

He said the more coverage around the eyes, the better. Lenses should be dark enough so "you can't see your pupils when you look at yourself in the mirror", but not so dark they impaired your vision.

This summer's hottest style, the retro Ray Ban, didn't offer the wearer as much sun protection as the wraparound or shield styles, because of its "smaller shape, with gaps".

While price was not necessarily a reliable indicator of sunglass safety, it paid to know what you were buying. The Australasian standards for sunglass manufacturers are not mandatory - Sue advised consumers to be wary of glasses without compliance stickers. "Sunglasses on sale, like at the $2 Shop, may not comply with the standard."

He said ozone layer-deprived Kiwis were at high risk of developing sun-related eye problems such as cataracts or macular degeneration. "We spend a lot of time outdoors."

Eye conditions were especially prevalent in Maori and Pacific Islanders, or people who tended not to wear sunscreen or take sun-safety precautions, he said. While darker skin types could offer more natural protection from the sun's cancer-causing rays, the whites of the eyes remained vulnerable.

Cath Chittenden of the Cancer Society said cancer inside the eye was rare. But a large number of cancers formed on the eyelid, or around the eye.

She said price was "definitely not an indicator" in determining which sunnies were the safest. "Warehouse ones can be as effective as a pair of Serengetis."

She also suggested staying away from the "cheap cheap ones" which did not comply with the Australasian standard. "Your eyes are too precious not to know [whether they meet standard]."