Pentax Single Vision comes in 3 designs:
Pentax Single Vision (SV) is a range of contemporary lenses that is designed for urban professionals. With thinner lens, user can enjoy a natural view that feels comfortable and stylish at the same time.
Pentax AS and Pentax DAS HD suit users with moderate to high refractive errors. Not only is Pentax SV aspherical thinner and flatter, it also reduces distortion to provide users with a crystal clear view and wider range of vision compared to conventional spherical lenses.