Scleral lens

A scleral lens is a large lens that rests on the sclera and creates a tear-filled vault over the cornea. Scleral lenses are designed to treat a variety of eye conditions, many of which do not respond to other forms of treatment.

Design

Modern scleral lenses are made of a highly oxygen permeable polymer. They are unique in their design in that they fit onto and are supported by the sclera, the white portion of the eye. The cause of this unique positioning is usually relevant to a specific patient, whose cornea may be too sensitive to support the lens directly. In comparison to corneal contact lenses, scleral lenses bulge outward considerably more. The space between the cornea and the lens is filled with artificial tears. The liquid, which is contained in a thin elastic reservoir, conforms to the irregularities of the deformed cornea, allowing vision to be restored comfortably.

Indications for use

Scleral lenses may be used to improve vision and reduce pain and light sensitivity for people suffering from growing number of disorders or injuries to the eye, such as Microphthalmia, keratoconus, corneal ectasia, Stevens-Johnson syndrome, Sjögren's syndrome, aniridia, neurotrophic keratitis (aneasthetic corneas) and pellucid degeneration. Injuries to the eye such as surgical complications, distorted corneal implants, as well as chemical and burn injuries also may be treated by the use of scleral lenses.

Use in special effects

Special effect scleral lenses have also been used to produce eerie eye effects in films, such as the whited-out eyes of the monsters in Evil Dead, or blacked-out eyes in Underworld and Underworld: Evolution. These lenses tend to be uncomfortable and sometimes impede the actors' vision, but the visual effects produced can be striking. The lenses cost around $300, are custom-made to fit the wearer's eyes and can also be custom-painted, although most companies only sell lenses with a pre-designed look. There are many different designs available, from standard black lenses to flame-effect eyes, as well as a lens that makes the whole eye white. However, the wearer is unable to see anything while the latter variety of lens is worn. If looked after, the lenses can be kept for around one year. It is recommended that they be worn for a maximum of 5-6 hours at a time, and only occasionally.

External links

• Use of Scleral lenses in Keratoconus
• Scleral lenses
• Scleral Lens Education Society
• Boston Foundation for Sight
• Sclerals.com
• 9mm Special Effects Lenses
• Scleral lenses used for ocular surface diseases