Biomaterial Database

Flexure of rigid contact lenses on toric corneas as a function of base curve fitting relationship. 1983

J P Herman

This study examined flexure of contact lenses while varying the base curve corneal relationship. Identical 9.5 mm lens designs of Polycon I, Polycon II and PMMA and Polycon I 9.0 mm lenses were fitted to corneas with toricities of between 0.75 and 5.00 D. It was found that the amount and direction of the flexure were determined by the base curve fitting relationship. As lenses were fitted steeper than K, with-the-rule flexure occurred, and flatter than K, against-the-rule flexure. If the upper lid covers the superior portion of the lens, an against-the-rule flexure component is usually introduced.

UI	MeSH Term	Description	Entries
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
D010539	Permeability	Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.	Permeabilities
D012030	Refractive Errors	Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus.	Ametropia,Refractive Disorders,Ametropias,Disorder, Refractive,Disorders, Refractive,Error, Refractive,Errors, Refractive,Refractive Disorder,Refractive Error
D003261	Contact Lenses	Lenses designed to be worn on the front surface of the eyeball. (UMDNS, 1999)	Lenses, Contact,Contact Lens,Lens, Contact
D004548	Elasticity	Resistance and recovery from distortion of shape.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man