OPTIONS for contact lenses. Not worn during the day.
Orthokeratology (ortho-k) involves the use of rigid lenses of a special design worn overnight only, to adapt the shape of the cornea (the window of the eye) to allow perfect sight during the day.
It is generally only for short-sighted (myopic) individuals who require a corrective lens of up to -4.00D and a small amount of astigmatism.
Ortho K gives freedom from day time wear. You can swim, shower and SEE without lenses in during the day.