Cheap vs Expensive Sunglasses

The health question, settled first

The genuine concern with cheap sunglasses is a specific and reasonable one: dark lenses cause your pupils to dilate, and if those dark lenses do not block UV, more ultraviolet light reaches your retina than if you wore nothing at all.

That risk is real, and it is also easy to eliminate. UV-blocking is achieved with a coating or an additive in the lens material that costs a trivial amount, and virtually all sunglasses sold by legitimate retailers in regulated markets are compliant. Polycarbonate, the most common cheap lens material, blocks essentially all UV inherently.

What to look for: a label stating UV400 or 100% UVA/UVB protection. Where it is absent - a market stall, an unlabelled import - the risk is genuine and we would not wear them.

So: buy labeled sunglasses from a legitimate retailer and the health question is answered at $15. Everything below is about quality, not safety.

Where cheap sunglasses genuinely fall short

Optical distortion. Cheap lenses are injection-molded quickly, which leaves slight variations in thickness. Over a few minutes you will not notice; over a day of driving or on the water it produces real eye strain and headaches. This is the most legitimate reason to spend more.

Scratch resistance. Uncoated polycarbonate is soft. A pair kept loose in a bag will be visibly scratched within a few months, and scratches scatter light, which is both annoying and tiring.

Hinges. The hinge is where almost every pair of sunglasses dies. Cheap hinges are two pieces of thin metal through plastic, and they loosen and then snap. Sprung hinges on better frames last years.

Polarization quality. A cheap polarizing film laminated to a lens can delaminate or craze with heat - a car dashboard in summer is exactly the environment that does it.

Buy cheap if...

You lose or sit on sunglasses regularly, which is most people. You want several pairs - one in the car, one in a bag, one by the door - which is genuinely more useful than one good pair you can never find. Or you wear them occasionally rather than all day.

The rational strategy for the majority of people is two or three cheap labeled pairs kept where you need them, replaced without regret when they scratch or break.

Buy expensive if...

You wear them for hours at a time - driving for work, on the water, cycling, skiing. Optical distortion over long periods is a real cost, and better polarization genuinely reduces glare more effectively.

Or if fit is a problem for you. Prescription-grade frames come in multiple sizes with adjustable nose pads, and a pair that actually stays on your face is worth paying for.

Or if you want something repairable that you will keep for a decade, where replacement lenses and arms turn a $250 purchase into a long-term one.

What we would not do is buy expensive sunglasses believing they protect your eyes better. They do not, and that is the claim this page exists to correct.

Polarization, briefly

Polarized lenses filter out light reflecting off horizontal surfaces, which removes glare from roads, water and snow. The effect is dramatic and worth having if you drive or spend time near water.

Two caveats. Polarized lenses make LCD screens - car dashboards, phone screens, some aircraft instruments - hard or impossible to read at certain angles. And they are unsuitable for some activities, notably certain kinds of skiing where spotting ice depends on seeing the reflection.

Polarization is available from around $20 and is a better upgrade than a darker tint. Tint darkness has nothing to do with UV protection, which is the most persistent misunderstanding in this category.