The main purpose of Ortho-K is to be free of both spectacles and contact lenses for the majority, or more typically, all waking hours.
The freedom from any artificial aid appeals to spectacle and contact lens wearers and is ideal for sportspeople, those who work in dusty or dirty environments or people who find spectacles and conventional contact lenses inconvenient.
In addition, those who need to have a certain degree of uncorrected vision to satisfy their employers or a licensing body (e.g. pilots, police) can also be helped by Ortho-K. Most patients wear the lenses overnight and remove them on awakening, although some patients wear them solely during the day.