Where should scleral lenses be placed for proper fitting?

Scleral lenses are designed to vault over the cornea and rest on the white of the globe, known as the sclera. This placement allows the lens to create a tear-filled reservoir between the lens and the cornea, enabling proper oxygen delivery and providing comfort to the wearer. The lens must fully encompass the cornea and rest on the sclera to achieve the intended therapeutic effect and avoid discomfort, which is why maintaining proper fitting on the sclera is crucial.

When placed directly on the white of the globe, the lenses can provide optimal vision correction and comfort, filtering out irregularities in the surface of the cornea. This positioning is essential in conditions such as keratoconus, severe dry eye, or post-surgical corneal irregularities, where standard lenses may not perform adequately.

Other options do not provide the appropriate location for fitting scleral lenses. For example, placement in the inferior cul-de-sac or on the medial canthus would not achieve the necessary clearance over the cornea and could lead to lens instability or discomfort. Similarly, resting on the inferior lid would not allow the lens to function correctly and could cause it to dislodge or be uncomfortable for the wearer. Therefore, direct placement on the sclera is the correct