Don't spend a ton of money on the sunglasses unless you need Rx sunglasses. Fancy name brand sunglasses are a scam - they're all owned by the same company that creates a false sense of competition between their brands. This allows them to keep prices up on Ray-Ban and other expensive brands. Look up Luxxotica.

If you're purchasing sunglasses for daily wearing and you know you'll be wearing or carrying them into situations, just get a comfortable pair of cheapo polarized sunglasses from Walmart. Expensive sunglasses lose value as soon as they're purchased and if you scratch them, they'll be functionally and financially worthless from that point forward. Comfort is the most important thing, followed closely by style.