e/Base curve radius

Information
has gloss	eng: Base curve radius, abbreviated BCR or BC, is a parameter of a contact lens. Typical values are from 8.0 to 10.0 mm. The base curve is the radius of the sphere of the back of the contact lens that the prescription describes. Contact lenses must fit well to the wearer's cornea in order to be comfortable and to facilitate tear exchange and oxygen transmission.
lexicalization	eng: Base curve radius
instance of	(noun) a thin curved glass or plastic lens designed to fit over the cornea in order to correct vision or to deliver medication contact, contact lens