This technique turns contact lens fitting on its head! Special rigid gas permeable contact lenses are worn at night so no correction is needed during the day. Overnight wear has a temporary molding effect on the cornea (the front surface of the eye) to flatten the eye and reduce low degrees of myopia.
Suitable candidates have the beginning stages of shortsightedness or myopia and do not want to wear contact lenses or spectacles during the day. Soft contact lens wearers who suffer discomfort during the day like this form of vision correction.
Ortho K, as it is commonly known as, depends on two things to have its precise effect: firstly corneal topography to map the front surface of the eye and secondly new generation contact lenses made on computerised lathes to create the special curves. The effect on the cornea is gentle as there is hydrostatic pressure and suction zones accurately centred on the cornea.
Clearer unaided vision starts after the first night of wear. The lenses need to be worn every night to maintain the refractive effect.
This gives freedom from spectacles and is an alternative to laser refractive surgery.