Lens tint

Copper and amber tints cut blue light, which raises contrast and makes shapes stand out against a green or brown background. That is why they dominate freshwater: they help you pick a bass out of weed and read a bottom transition.

Grey tints are neutral. They dim everything equally without shifting color, which suits very bright open water and long drives, and they are the more comfortable choice for all-day wear in glaring sun.

Green and blue mirrored tints sit in between and are common on saltwater lenses. Yellow and rose tints raise contrast dramatically in low light, at the cost of being too bright for midday.

Light transmission is the number behind the color, quoted as a percentage. Around 10 percent is a bright-sun lens, 15 to 20 percent suits variable conditions, and 30 percent and up is for overcast and dawn.

Photochromic lenses shift between those bands automatically. They are a genuine convenience and they never get as dark as a dedicated bright-light lens.