Introduction Congenital or developmental abnormalities of corneal topography include primary corneal ectasias, such as keratoconus and keratoglobus, and cornea plana ( Fig. 25.1 ). These atypical corneal shapes provide significant challenges to clinicians who are attempting to restore vision for…
Introduction The use of soft toric lenses (in preference to spherical soft lenses) is indicated when there is ocular astigmatism present, be it corneal or noncorneal, that warrants correction. Unlike rigid lenses, soft lenses do not mask corneal astigmatism but…
Fitting Rigid Toric Lenses Indications for the use of rigid toric lenses Rigid toric lenses are indicated in preference to rigid spherical lenses under the following circumstances: ■ to improve vision in cases where a lens employing spherical front and…