Unfortunately Ortho-k lenses are not suitable for people with strong prescription. It is most effective for correcting up to -4.00 diopters of myopia and up to -1.50 D of astigmatism. Also people who have poor hygiene, inability to handle the lenses, severe dry eye, inflammations, infections and other problems are not good candidate for Ortho-k lenses.
Ortho-k lenses may not be effective for you if you have relatively strong prescription. Doctors find that people whose prescription is weaker than -4.00 diopters of myopia and -1.50 D of astigmatism can get successful result from wearing Ortho-k lenses.
No. Ortho-k lens is not effective for people who have strong prescription. It is only approved for mild to moderate prescription. So if you have strong prescription, you are not a good candidate for Ortho-k lens. You should go for other treatments.