When it comes to sunglasses, it took me a while to realise that you really do get what you pay for. Before spending £80 on these Oakleys, I'd bought, worn and broken a succession of cheap knock-offs touted by beach salesmen - sure, they looked pretty good and cost a whole lot less than the real thing, but when you have to replace a busted pair every six months, having sat on, looked at, or breathed in the approximate vicinity of them, it becomes something of a false economy.

Knocked down from £100 or so when I bought them, these glasses aren't a cheap option - but the difference in quality becomes self-evident. Eight years on, they're still going strong, with barely a scratch or scuff on them. For me, that's value.

In the Oakley pantheon, this model - Fives - are a fairly restrained, clean-cut option. The manufacturers produce some pretty bombastic, straight-off-the-ski-slope glasses, featuring mirrored lenses, neon frames and built-in earphones, but this is your common-and-garden variety eyewear. The styling is toned-down and subtle, but the touches are there that make these glasses typically Oakleyesque.

From a design point of view, there are a number of touches that attract me to Oakleys - and in particular this specific model. For me, they tread a happy aesthetic line, being attractive and distinctive-looking without looking overworked and gimmicky. There's a golden "O" logo on each arm and the Oakley name printed across the bridge, but on the whole the look is clean and simple. The lines of the glasses are wonderfully smooth, forming a series of continuous sweeping lines when worn - this a nice in-between product, featuring the kind of styling seen in wraparound sports glasses alongside a pared-down feel that doesn't look out of place off the beach or track.

Practically speaking, these score extremely highly too - Fives are exceptionally lightweight glasses, so much so that it's easy to forget you're wearing them - or think you still are after you've taken them off. At the same time, though, they don't feel flimsy - I often wear them for running and they grip well, never slipping yet retaining their weightless feel. The rubber ends to the arms retain an impressive hold on your head without pinching or making you too aware of their presence.

Strength-wise they're also great - I've broken enough pairs of inferior glasses to recognise a hardy, resilient pair - and these excel. They've been dropped countless times, and jammed into the bottom of innumerable rucksacks in just the case they came in. For all this rough treatment, though, you wouldn't guess at their age - aside from a wearing-away of the Oakley logo on the bridge, they're practically unmarked, a couple of very minor scratches on the lenses the only other hint of their history.

Naturally, colourways vary, but mine are a translucent tortoiseshell. As a kind of smoky, mottled chocolate-brown, they look better than they sound. The lenses are slightly tinted, casting everything in sepia tones - yet this isn't nearly as distracting or intrusive as it sounds. Colours come through well, and the lenses are quick and easy to clean with the bag they come in or a handy t-shirt edge.

I've bought a second pair of Oakleys since for variety's sake, and have found much the same to sing about in these - this is a solid, reliable brand that pours no small amount of effort and detail into its products, and despite the relatively high initial outlay, you'd need to be pretty clumsy to work your way through more than two or three pairs per decade. Given the importance of the product (and naturally, the lenses meet all appropriate guidelines and offer excellent protection from the sun), they strike me as an extremely good investment.