Single visions lens are best in frames to fit people who have myopia or near sightedness ,or hypermopia which refers to far sightedness. If you need a pair of reading glasses single vision lens can help you there. You can even fancy up your single vision eye glasses by getting transitional shading crafted into the lens. Go from sunshine to shadows while keeping your smiles. Without that blurry temporary loss of vision that is associated with going from bright outside sunlight to the semi darkness.