For children’s optometry, regardless of myopia, hyperopia or astigmatism, it is necessary to perform pupil dilatation because the ciliary muscle of children’s eyes is very elastic and has a very strong adjustment ability. There have been clinical cases where children with two or three hundred degrees of hyperopia have shown up as one or two degrees of myopia with very large errors because the pupils were not dilated prior to the optometry. Obviously, to give the child glasses based on this error, it will be harmful to the child’s eyes. Therefore, it is important to have a dilated eye exam in order to understand the objective and true refractive state of your child’s eyes. Dilated eye examinations are not harmful to the eyes. The action of the dilator causes paralysis of the ciliary muscle and dilates the pupil, resulting in photophobia and blurred vision. Rapid dilators wear off in 6 to 8 hours and the pupil returns to its original state. Slow dilators, or atropine, may take 2 to 3 weeks to wear off. A small number of people may experience redness, dry mouth, dizziness and panic when using atropine for pupil dilatation. Pupil dilators are contraindicated in people with glaucoma or a tendency to elevated intraocular pressure.