First and foremost, it's important to stress that these contacts aren't suitable for everyone, and as with any new contacts you must first see a specialist to determine whether your specific condition can be treated with reshaping lenses. After initial examination, the next step would be a measurement of the curvatures of your corneas using an instrument called a corneal topographer . None of these procedures is painful in any way and you are basically asked to look through a series of lenses while the eye doctor evaluates your reaction and the reaction your eyes display. It's also quick and effective in producing a kind of topographical survey of your eye and your range of eyesight. 20/40 vision is considered acceptable and it's the legal visual minimum for driving in most of the United States .
Many doctors believe the best candidates are people who have low amounts of myopia, about -4.00 diopters or less. Worn at night, the contact gently reshapes and re-flattens the surface of your eye, so you can see clearly even after you remove the lenses. As myopia occurs as a result of light passing through the cornea into the eye in such a way that it doesn't focus properly on the retina, this specially designed lens flattens out the cornea and allows light to focus correctly on the retina. This product is for people of any age who are nearsighted with up to six diopters of myopia (-6.00 on your prescription). The effect only lasts long enough to get you through a day or so, but you must wear the special lenses each night for them to work. This reforms the cornea back to its natural and healthy state, resulting in better vision.