Perfect for your first pair of glasses, glasses for children or standard everyday glasses: ZEISS single vision lenses are used for both distance vision and reading – the two most common reasons people wear glasses. What's the difference? With reading glasses, the single vision lenses are optimized for vision in the near zone and personally fitted to the farsighted reader's standard reading distance. These lenses are great not only for books, but also for reading smaller font sizes on a smartphone or tablet. Farsighted wearers usually have blurry vision in the near zone and sometimes when looking into the distance. Farsightedness results from an image being focused behind the retina, resulting in a blurry image. With nearsightedness, however, objects in the distance appear blurry because the nearsighted eye focuses images in front of the retina rather than on it. An optimally fitted pair of distance lenses can help you see clearly when looking at objects which are far away.