A refraction eye test determines what prescription you need for your glasses. During the test, you will be asked to read a chart usually six metres away by looking through a special instrument known as a phoropter. The doctor changes the lenses in the phoroper to choose the one that best suits the patient. If you have vision problems such as presbyopia, hyperopia, myopia and astigmatism, you should take the test every two to three years to determine if they need a new prescription.
The refraction test is also called vision test, which is a simple process for eye doctor to check the person's eyesight. The person needs to read from a chart in 20 feet distance by a refractor. And the eye doctor would change the lenses of the refractor to select the best one that suits the person. The normal result should be 20/20 vision. Otherwise, the person should have vision problem so that he/she had better take the test every two to three years to check whether a new prescription is needed.
I am so sorry that you and your child suffer from that. Regret to tell you that there is not good way to treat keratoconus, there just some way to slow down the development, and enhance some vision. Some therapies are RGP, intrastromaclornealring, UV joint raboflavin irradiation therapy and keratoplasty. Hope helps.