Ortho K, a vision therapy using orthokeratology uses contact lenses worn at night to correct the curvature of the eye. In the morning, the lenses are removed and you can see perfectly. Orthokeratology works by flattening the cornea so that it is a less powerful lens. Once the full effect has taken place, the eye is effectively ‘normal’ and can see clearly during the day giving freedom from glasses or contact lenses. This is really good for sports people and those who suffer from dry, irritable eyes. There’s also some evidence that Ortho K can reduce or stop the progression of short sight in teenagers.