When inserting a GP lens, it is placed:

Inserting a gas permeable (GP) lens directly on the cornea is the correct practice. This method ensures that the lens directly contacts the eye where it is intended to rest. The fitting of GP lenses requires precise positioning to enable optimal vision correction and comfort. When placed on the cornea, the lens allows for the natural tear film to create a layer of moisture, which is essential for proper wear and comfort.

Placing the lens directly on the cornea also facilitates the intended refractive properties of the GP lens, allowing it to align correctly with the visual axis of the eye. This positioning aids in providing clear vision without causing unnecessary manipulation or discomfort during insertion.

This contrasts with other methods, such as placing the lens on the eyelid or the sclera, which would not provide the necessary alignment or adherence needed for effective wear. Using a lens holder is also not the standard method for direct lens application, as it is primarily utilized to maintain the lens in a stable position during handling, rather than for insertion. Thus, the preferred approach is to place the lens directly onto the cornea.