Begin with protection, fit, and purpose: ensure UV protection, good lens quality, wrap‑around coverage, and a secure, comfortable fit during activity.

Look at lens protection (UV and polarization if needed), lens interchangeability or availability of replacement lenses, frame size/shape for a snug fit, and overall weight and durability.

For cycling or running, prioritize a secure wrap and ventilation; for future versatility, check if lenses are replaceable or whether there are options for different light conditions (tinted or photochromic lenses).

Choose darker, possibly polarized lenses with good glare reduction and a secure fit; ensure compatibility with your helmet or headgear and confirm that the frame size suits your face for all-day wear.