Smith has a bunch of lenses in the 12-15% VLT range, Black Iridium are 10% VLT. Julbo Arcs are 5% VLT.
I've found for really bright days (spring, new snow, 12k') the 5% is useful, otherwise it's overkill. Sportwraps get nasty sweaty and are way more uncomfortable to wear on a long day.