A lens shape must be chosen for rimless glasses. Click the “Select a Lens Shape” link and a pop-up will open. If you wear bifocals or progressives, you can only choose from the lens shapes on the Progressive/Bifocal tab. If you wear single vision lenses, you can choose from any of the displayed lens shapes on Single Vision tab.
Lens shapes are only available in the size displayed. Keep in mind that a really wide lens will result in wide glasses. Choose a lens shape with a lens width similar to what you currently wear and not just by the shape of the lens.