For decades optometrists have been fascinated by the possibility short-sightedness and other vision problems could be cured by simply changing the shape of the cornea, the surface of the eye. Get the method right, goes the thinking, and glasses could be a thing of the past.
In the 1980s, a surgical method whereby a laser is used to cut and change the shape of the cornea, overcame scepticism to become a medical boom industry.
But there is another - much older - method which involves no cutting or operating.
This method, orthokeratology, has been around for 40 years and is based on observations that if you put a specifically shaped hard lens on the eye, it will put pressure on and alter the shape of the cornea. Because it is the cornea which has changed shape in the two most common forms of visual disturbance, myopia (short-sightedness) and astigmatism, altering it to its correct shape should restore normal vision.
Orthokeratology works something like orthodontistry. The way it was originally practised, optometrists would use a series of hard lenses on their patients to slowly correct the shape of the cornea until it was normal, or close to normal. However, despite the soundness of the theory, in practice it was rarely successful. So disappointing were the results it was dismissed as a fringe therapy hardly worthy of attention, by ophthalmologists.
Despite its poor results and general dismissal, a small band of optometrists has persisted with it.
