Types of Eyeglass Lenses
After materials, Essilor lens makers consider the design and function for every type of eyeglass lens. Does the wearer need them to see far away or up close? Are they correcting a vision problem, such as astigmatism? Here are just some of the lens designs to meet those vision needs:
- Single vision lenses—made for one, consistent focal power to correct a single vision condition.
- Progressive lenses—correct more than one vision condition, with the focal power “progressing” from top to bottom without a visible line separating them.
- Concave lenses—used to treat near-sightedness, or myopia. The lens shape is concave (thicker at the edge, thinner in the middle) to bend rays outwards.
- Plus lenses—used to treat far-sightedness, or hyperopia. The lens shape is convex (thicker in the middle, thinner at the edge) to bend rays inwards.
- Cylindrical lenses—designed for astigmatisms, or when the cornea of the eye is oval, rather than round. A cylindrical lens is the most common way to correct astigmatism.