Monofocal Foldable lenses can be biconvex and aspheric in design. Aspheric foldable IOLs reduce spherical aberration, improve functional vision and improve performance in a night-driving. A standard monofocal IOL is a fixed lens (it doesn't move). It is designed to deliver improved vision at just one distance (usually far). The potential drawback is that after surgery, you will probably need to wear glasses for near and intermediate vision, even if you didn't wear glasses before surgery.