Look for 100% UV protection (UV400), glare-reducing polarization if you’ll be outdoors in bright light, a suitable lens category for typical conditions, and a comfortable, durable frame.

Key attributes are lens type (polarized vs non), UV protection level, lens tint/material, frame fit/size, and overall durability.

Consider coatings (anti-scratch, water-repellent), lens colors that enhance contrast for your activity, and whether interchangeable lenses or additional accessories are available.

Cycling benefits from a secure wrap and good ventilation; driving benefits from strong glare reduction; hiking favors a balanced tint and rugged durability.