The short answer’s yes, the higher the [lens index](/prescription-lens/lens-index), the thinner the lens, which makes it lighter than a standard lens. But you should never choose a lens according to its weight. The lens thickness you receive depends on your prescription and vision correction needs. Thinner lenses are lightweight, more expensive, and naturally more stylish. They accommodate all kinds of vision correction needs, including higher prescriptions. A 1.5 lens index is thicker than a 1.74 lens index, the latter being the thinnest lens we offer at EyeBuyDirect.