The cure for astigmatism should be the earlier the better.You should take your child to a regular hospital for an eye exam. If the vision is below the normal level, the doctor can give the child atropine eye ointment for pupil dilation and then wear appropriate glasses for correction.
No, there is no age limit for therapeutic astigmatism. Astigmatism can occur at any age. Once it is found, it must be treated immediately for recovery.
My son have astigmatism, but as he grows up, it gradually goes away. The doctor says that if an adult have this eye disease, he should have prompt treatment as soon as possible.