Thinner, lighter high-index lenses are especially recommended if you have a strong eyeglass prescription for nearsightedness, farsightedness or astigmatism.
Most of today's fashionable frames are made of plastic or metal with rims thinner than the lens itself. Also, popular rimless mountings mean that the edges of the lenses are completely exposed. In either case, the lens edges are highly visible, and thicker edges can detract from the appearance of your eyewear.
High-index eyeglass lenses are the right choice if you want thinner, lighter lenses and eyeglassesthat are as attractive and comfortable as possible.