Sunglasses: check UV protection first

Read the label

Visible light lets us see brightness and colour. Ultraviolet radiation is outside that visible range. A tint that makes a scene darker tells you about visible-light transmission, not by itself about ultraviolet protection. A clear material can include UV protection, while an unknown dark lens cannot be judged by appearance. Polarisation is a third property: it can reduce certain reflections but should not be used as a substitute for checking UV specifications.

The National Eye Institute advises choosing sunglasses that block 99 to 100 percent of UVA and UVB radiation. Check the stated protection rather than judging it from the darkness of the lens.

Match the pair to its purpose

Ask for prescription compatibility and the intended use of the tint. Keep the UV specification with your order so you can distinguish protection information from colour and style preferences.

A worked example

Compare three labels separately: documented UVA/UVB protection, tint or light-transmission category, and polarisation. Then consider whether the frame covers the eyes comfortably. For example, a very dark fashion lens may be unsuitable for a low-light journey even if it has good UV protection. Sunglasses are also not eclipse-viewing equipment. The useful skill is matching a documented function to the task rather than selecting the darkest lens on the rack.