single vision glasses are designed to help people who need correction of farsightedness, nearsightedness or astigmatism. these lenses have just a single optical preion correction and they distribute focus evenly over the entire surface area of the lens... recomemded for powers below 6 sph & 2 cyl. this premium blue block arc lens offers active protection to your eyes against harmful uv and blue rays. greatly reduces eye fatigue to active computer and mobile devices users.