How can I compare sports glasses for different activities?

List the usual light, posture and equipment for each activity, then check fit and lenses against those needs. A shared sporty appearance does not mean two designs offer the same coverage, helmet compatibility or technical features.

When might photochromic lenses be useful?

They may suit routes with changing light. Compare their tint range and stated conditions; do not assume that every photochromic lens suits every level of brightness.

What should I check in sunglasses when looking down a trail?

Check that the lower rim does not obstruct your view of the ground and that the frame stays stable when you lower your head. Compare coverage with ventilation and fit. Try the sunglasses with your cap or other equipment instead of judging them only in a mirror.

Do darker lenses provide more UV protection?

Tint darkness and UV protection are different features. Check the stated protection and filter category; neither should be inferred from lens color alone.