Essilor International S.A. is a French-based international ophthalmic optics company that designs, manufactures and markets lenses to correct or protect eyesight. Its headquarters is in Charenton-le-Pont (near Paris), France.

Essilor is responsible for creating Varilux, the world's first progressive lens, which corrects presbyopia and allows clear vision in the wearer's near, intermediate and far vision. 

The company formed from the merger of ophthalmic firms Essel and Silor in 1972. Its activities are largely focused on research and development. It is the world's largest manufacturer of ophthalmic lenses.

In January 2017 Essilor announced a combination with Italian eyewear giant Luxottica. On 1 October 2018, the new holding company EssilorLuxottica was born, resulting in combined market capitalization of approximately €57 billion.

Essilor operates a worldwide network of production plants, prescription laboratories and distribution centers that supply corrective lenses, glasses and sunglasses to opticians, optical chains, and consumers (via e-retailers it owns and/or operates directly).

According to en.wikipedia