I've heard about gas-permeable contact lenses that you wear at night to reshape your cornea so contacts will not be needed during the day. I'm nearsighted and this sounds like a better solution than eye surgery. Can you tell me more?

K.K.

Orthokeratology (Ortho-K) is a nonsurgical form of vision correction that uses a special type of contact lens in an effort to reshape the eye's cornea. Ortho-K has the best chance of working on people who are nearsighted (myopic) because they tend to have steep corneas. When the gas-permeable Ortho-K lenses are worn overnight, they slowly flatten the cornea and gradually reduce the amount of myopia. In contrast, during LASIK and other types of laser eye surgery, doctors use a laser to quickly reshape and flatten the cornea, leading to rapid vision improvement.

Bear in mind that laser surgery produces permanent results, while orthokeratology's results are only temporary. For example, a person with mild myopia could potentially see without glasses if they wore Ortho-K lenses every night for several weeks. However, during the course of the day, the person might notice visual fluctuations as the cornea attempted to return to its normal shape. If the patient stops wearing the Ortho-K lenses, the cornea may return to its original shape -- and vision would return to the original degree of myopia -- in a matter of days or weeks. Also, Ortho-K lenses usually provide little help to people with severe myopia, while laser surgery can frequently improve the vision of severe myopics.

Another big drawback to Ortho-K is the risk of a corneal infection. Sleeping in contact lenses may cause the eyes to dry up, allowing the lenses to stick tightly to the corneas and increasing the chance of developing a possibly sight-threatening infection.

In summary, Ortho-K is an interesting method for trying to treat myopia, but it has found only limited success due to its risks and lack of permanency. If you are interested in orthokeratology, you should contact an expert in this procedure, usually an optometrist.