Consider how quickly lenses darken in bright light and fade back when indoors, the maximum darkness they reach, and how well they respond to UV exposure. Also check the lens material for durability and whether the frame and prescription fit, plus coatings like anti-scratch or anti-reflective for everyday use.

Key attributes are transition speed, the darkness range (how dark they get), activation wavelength (UV-based), prescription compatibility, and coatings such as anti-scratch, anti-reflective, or polarization where available.

For driving, prioritize strong glare reduction and, if possible, polarization. For indoor or screen use, consider lighter indoor clarity and coatings that minimize reflections; ensure the lenses match your prescription and frame style.

Choose lenses with fast activation and a suitable darkness level for bright sun, and check if you can add polarization or blue-light coatings if you need glare control or screen comfort. Verify frame compatibility and that the prescription is accurate.