Maui JimWomen's Cloud Break Polarized Fashion Sunglasses

Do these lenses block out the sun totally? I have never spent a lot on sunglasses but have had LASIK surgery and my eyes are more sensitive to sun

Can your eyes be seen though these lenses? what is the darkest option for maui jim lenses? thanks

What are the specs on sizing? Width, etc

How can I be sure these are authentic?