Overnight orthokeratology lens wear alters the anterior corneal shape rather than the posterior radius of the corneal curvature and the anterior chamber depth. This finding suggests that the primary factor in the refractive effect of orthokeratology is change in the anterior corneal shape rather than overall corneal bending.

Hydrogel lenses resist cosmetic cleansing oil. However, SHCLs have different degrees of resistance depending on the lens material. Some SHCLs absorbed cosmetic cleansing oil more under dry conditions than under wet conditions.