These goggles have corrective lenses for nearsightedness from -1.5 to -8.0 diopters. The increment starts at .5 diopters, but increases to 1.0 for stronger lenses. The lenses can be separated at the nose, so you could mix & match 2 sets if your eyes differ a lot. Lenses are clear or dark-tint polycarbonate. The lenses are molded, and thus not optically perfect, but at about $20.00 who can complain?
They are great for rolling practice, or rough water paddling such as surf or white-water. They are also good as an emergency backup if you loose your glasses. I usually have a set in my PFD pocket or have the strap around my neck if I'm not already wearing them.
