Scleral lens in practice

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A scleral lens per se is one that bears solely on the sclera. In order to give a minimum 1mm scleral bearing annulus and 1mm circumferential limbal clearance, assuming a corneal diameter of 12 mm then by definition a scleral lens must be 16mm or greater in diameter. The term has been more loosely applied to corneal lenses large enough to extend beyond the limbus in recent times which can confuse the issue somewhat.

The advent of RGP materials for the manufacture of scleral lenses has transformed the picture as the vast majority of cases can now be fitted from preformed trial sets with simultaneous assessment of optic and scleral zone characteristics.