This year’s 8-year-old second grade classmate Yu, class feel unable to see the words on the blackboard, parents rushed to find a nearby optical store with glasses, wear a period of time after Yu felt unable to see again. Children under the age of 13 and adolescents who are getting glasses for the first time should have a standardized dilated eye exam done by a medical professional to rule out other eye diseases and to screen for pseudomyopia. The dilated eye exam recommended by the ophthalmologist requires one dilated eye exam and one re-examination after the pupil has returned to normal. Some parents refuse to have a dilated eye exam for fear of the hassle or damage to their child’s eyes. So, why do children’s refractive examinations need to be dilated? Is it harmful to your child’s eye health? Let’s hear Dr. Pan’s answer to this question. What is refractive error? The eye is able to focus light from the outside world on the retina at the base of the eye to create clear vision. An eye that is unable to focus accurately is called a refractive error. Farsightedness, myopia and astigmatism are all refractive errors that affect focus, making it impossible for the eye to see outside objects and making vision worse. Testing the refractive state of the eye is called optometry. Astigmatism is an objective refractive examination performed with the application of medication to completely paralyze the ciliary muscle of the eye, causing it to lose its regulating effect. Since most ciliary muscle paralytics are anticholinergics that block the parasympathetic nerve, they paralyze not only the ciliary muscle, but also the pupillary sphincter, causing the pupil to appear dilated, which is why ciliary muscle paralysis optometry is also called “dilated optometry. Why do children need to have their pupils dilated for optometry? There are two purposes: First, children’s eyes are highly regulated, especially in children with hyperopia and internal strabismus, and after pupil dilation, the ciliary muscle is paralyzed and the regulation is relaxed, so that the refractive power of the eye is completely exposed. In addition, dilated pupils can also remove the adjustment factors of the eye, which can be used to identify true and false myopia. Second, dilated pupils allow the ophthalmologist to examine the child’s eyes in detail to detect and rule out organic eye pathology. Therefore, it is necessary for children with poor naked eye vision or for first-time examinations. Dilated eye examinations are mainly used in the following cases: (1) Children and adolescents. (1) Children and adolescents, whose eyes are highly regulated and whose refractive errors can be large if they are not dilated; (2) Adolescents with rapid loss of bare eye vision or suspected pseudomyopia; (3) Children with complex refractive errors, such as high myopia, high hyperopia or high astigmatism, or mixed astigmatism; (4) Patients with poor corrected visual acuity after small-pupil optometry, or with refractive interstitial clouding, should be dilated. (1) “Slow” pupil dilatation: Children within 13 years of age, especially those with hyperopia, amblyopia, and internal strabismus, should have their eyes dilated or coated with atropine eye drops or gel or ointment three times a day for five days, and then have their pupils dilated. The pupil should be dilated for 5 days and then examined again after the pupil has returned to normal in about 3 weeks. Since it takes a long time for the pupil to dilate and recover, it is generally appropriate for school-age children to be examined during the winter and summer holidays. (2) “Rapid” pupil dilatation: Students over 13 years old and children with myopia should use cyclopentolate (cyclopentone) or tropicamide drops to spot their eyes every 5 to 10 minutes, 3 to 4 times, and then have their eyes examined one hour later and retested the next day after their pupils have returned to normal. Is astigmatism for children harmful to the eyes? Dilated eye examinations are not harmful to the eyes. Many parents are concerned about dilated eye exams because they do not understand what is going on with dilated pupils and are afraid that their child’s eyes will be damaged if their pupils are dilated. The photophobia and blurred vision in children after pupil dilatation are the result of medication. (1) The common dilating drops used in optometry are atropine, cyclopentone, and tropicamide, which block the excitatory effects of cholinergic nerves on the pupillary sphincter and ciliary muscle, causing the pupil to dilate and the ciliary muscle to become paralyzed. As the pupillary sphincter is paralyzed and the pupil opens wide, it cannot control the amount of light entering the eye, thus causing photophobia. (2) When the ciliary muscle is paralyzed, the phenomenon of blurred vision of near objects occurs when looking at something near. This phenomenon occurs under the effect of pupil-dilating drugs, and once the effect of the drug is diminished, these symptoms disappear. Atropine eye drops are usually discontinued for about 3 weeks after which the eye regulating effect gradually returns and the pupil returns to normal. The pupils of cyclopentone and tropicamide gradually return to normal after about 6 hours. (3) After ordering atropine eye drops or applying gel, be careful to press the inner canthus of both eyes (the tear sac at the root of the nose) for more than three minutes each time to prevent the drug from flowing into the mouth and nose through the tear dots and being absorbed into the body. Individual children may experience facial redness, eye redness, dry mouth, rapid heartbeat, or even hypothermia after using dilating medications (especially atropine eye drops), which usually do not require special treatment and will disappear after stopping the medication. Myopia and its prevention have become an important health issue for the whole society. Children and adolescents are at the stage of growth and development and should have their eyes examined at least once every six months (dilated eye examinations should be conducted by a professional doctor at a regular hospital ophthalmology department) in order to have accurate eye examinations and scientific prescriptions to truly protect our “windows to the soul”. The “window of the soul”.