
Types Of Scleral Contact Lenses
Scleral contacts are noticeably larger than standard gas permeable (GP) contacts and have a diameter equal to or greater than that of soft contact lenses. The smallest sclerals are approximately 14.5 mm in diameter, and the largest can be up to 24 mm.
Large-diameter scleral and semi-scleral GP lenses rest on the sclera and vault over the misshapen cornea of a person with keratoconus, for better vision.
Corneo-scleral lenses often are a good choice for people who require larger-than-normal GP lenses for greater comfort. They also are frequently used when contact lenses are needed after LASIK or other corneal refractive surgery to correct irregular astigmatism.
The size of lens used often is determined by the degree of complexity of the condition. Milder forms of keratoconus and irregular astigmatism from corneal grafts and refractive surgery often are easily managed with scleral lenses at the smaller end of the spectrum.
Smaller scleral and mini-scleral contacts can be easier to apply, can be less costly and require fewer care products.
More complex conditions, including advanced keratoconus, pathologically dry eyes or severe ocular surface disease that might require a large tear reservoir, often are fitted with larger scleral lenses, as they have more capacity to hold fluid or bridge large changes in corneal curvature.
During your contact lens exam and fitting, your eye care professional will determine the best scleral lens type and size for your specific needs.