Scleral lenses are literally lenses that cover both the cornea and the anterior sclera.

They are sometimes referred to as "haptic" lenses. For about 60 years they were the only lenses available.

Vision improvement

The main indication for the use of scleral lenses is the correction of irregular corneas in order to restore vision. The largest segment of this category are corneal ectasias, which can be divided into two groups. The first is the major group of corneal ectasias, which includes keratoconus, keratoglobus, and pellucid marginal degeneration. The second group includes post-refractive surgery ectasias, LASIK, LASEK, PRK, and postkeratotomiaradial (RK), and trauma. Corneal transplants, especially the penetrating keratoplasty technique, often require a postoperative contact lens to fully restore vision. A scleral lens may be indicated in many of these cases. Scleral lenses are also indicated for other types of irregular corneas with the primary objective of restoring the quality of vision such as, for example, corneas with post-traumatic astigmatism. Eyes and corneas with significant and severely irregular scarring from trauma can achieve optimal vision with scleral lenses—often to the surprise of both the patient and the practitioner. Corneal scarring following corneal infections, particularly from Herpes simplex, are a further indication for the fitting of scleral lenses.

Corneal protection

There is a large group of patients presenting with expository keratitis / ocular surface disease in which the use of scleral lenses is particularly advantageous for maintaining a fluid reservoir behind the scleral lens. Sjögren's syndrome is a common indication for scleral lens wear. Also included in this category are conditions such as persistent corneal epithelial defects, Steven Johnson syndrome, graft versus host disease, cicatricial ocular pemphigoid, neurotrophic corneal disease, and atopic keratoconjunctivitis. A scleral lens may be a good indication if lid closure is incomplete, such as in lid coloboma, exophthalmos, ectropion, nerve palsy, and after lid retraction surgery