What type of glasses should i choose?

What type of glasses should i choose?

Distance Single Vision -- If you only need distance correction, including astigmatism, choose distance single visoin glasses. 

Bifocal -- If you want to have both distance and reading prescription on one lens, choose bifocal.

Progressive -- progressive is also called no-line bifocal, acutally it provides seamless progression of many lens powers for distance, intermedia and reading correction. If you do not want "vision jump" effect of bifocal, and want to view all distance with one glasses, progressive is your choice. One reminder: pick large frame height (30mm or larger) for progressive, if frame height is too small, you will have problem viewing.

Non-Prescription -- If you want a frame for cosmetic purpose, or a non-prescription sunglasses, pick this one.