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2022

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Why do glasses need to be dilated optometry?

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my country is a big country of myopia. With the popularization of computers and mobile phones in today's society, the incidence of myopia is getting higher and higher, and the age of myopia onset is getting earlier and earlier. When fitting glasses, optometrists often ask young myopic patients to undergo pupil dilation optometry. Many people do not understand it and feel that it is slow and troublesome and are unwilling to dilate their pupils. So what are the problems if glasses are not fitted with mydriasis?

my country is a big country of myopia. With the popularization of computers and mobile phones in today's society, the incidence of myopia is getting higher and higher, and the age of myopia onset is getting earlier and earlier. When fitting glasses, optometrists often ask young myopic patients to undergo pupil dilation optometry. Many people do not understand it and feel that it is slow and troublesome and are unwilling to dilate their pupils. So what are the problems if glasses are not fitted with mydriasis?

The human eye is like a camera with automatic zoom. The lens in the human eye is like the zoom lens of a camera. The retina is like the light-sensitive element of a camera. The lens thickens or thins so that the near or far light is precisely focused on the retina, so that the human eye can see objects at different distances. The most critical step is the process of changing the thickness of the lens, which is mainly achieved through the ciliary muscle.

The ability to "focus" the ciliary muscle

The ciliary muscle is a smooth muscle arranged in a ring inside the eye. When we want to focus on a distant object, the ciliary muscle will naturally relax and tighten the ligament that locates the lens, so that the lens will become flat and thin. Reduce the focusing ability of the lens, which helps us see things at a distance. When looking at distant objects, the ciliary muscle relaxes and tightens the ligaments that locate the lens, which flattens the lens and reduces the ability of the lens to focus; when looking at near objects, the ciliary muscle contracts, the ligaments that locate the lens relax, and the lens thickens and strengthens Lens focusing ability. It can be seen that the ciliary muscle plays an important role in the "automatic zoom" process of the human eye, and this ability to "focus" is called the adjustment function of the ciliary muscle.

The accommodation capacity of the ciliary muscle decreases with age. Young people, especially children, have a strong ability to adjust ciliary muscles. If the ciliary muscle is in a contracted state for a long time, it will cause ciliary muscle spasm. If the eyes are also in a state of ciliary muscle contraction when looking far away, It will cause blurred vision in the distance, but after the ciliary muscle is relaxed with drugs, the distance can be seen clearly, which is "pseudo-myopia", also known as "accommodative myopia"; and myopia still exists after the ciliary muscle is relaxed, which is It's "true myopia". It can be seen that the ciliary muscle needs to be relaxed in order to obtain the correct degree during optometry, and the mydriatic drugs play the role of paralyzing the ciliary muscle and eliminating "pseudo-myopia".

Are there any side effects of mydriatic pills?

Mydriatic drugs, also known as cycloplegic drugs, can be divided into two categories: rapid mydriatic drugs and atropine. The main component of the rapid mydriatic drug is topicamide, which has a fast onset time and a short maintenance time. It is suitable for people over 14 years old. Generally, optometry can be done 1 hour after the drug is ordered, and the pupil will recover after 4 to 6 hours. Atropine has a slow onset time, a long maintenance time, and a stronger cycloplegic function. It is suitable for children under 14 years old. Generally, it takes 3 to 5 days to take medicine before optometry, and the pupil recovers after 3 weeks. Strong light stimulation should be avoided during mydriasis, and a brim hat or sunglasses should be worn outdoors. In addition, mydriasis is to relax the adjustment of the ciliary muscle, so do not use the eyes at close range during the dilation, such as reading books, watching TV and using a computer, otherwise the ciliary muscle is not fully relaxed, and it will also affect the correct fitting of glasses.

It is safe for most people to order mydriatic drugs, but a small number of elderly people may induce glaucoma after taking mydriatic drugs. Very few children have obvious facial flushing, thirst, fever, headache, nausea, visual hallucinations and other symptoms after instilling atropine. It is considered as an adverse reaction of atropine, and the drug should be discontinued immediately and an ophthalmologist should be consulted.

Is the optometry process completed after pupil dilation?

The results of mydriatic optometry objectively reflect the static refractive state of the eye, but is it possible to obtain a suitable prescription for glasses based on this alone? not enough. Because people are usually in a state where the ciliary muscle is not paralyzed, it is also necessary to wear the diopter lens with the diopter detected during the dilated optometry after the cycloplegic effect disappears. , for clear, comfortable and long-lasting optimal fitting results. Therefore, re-examination is usually carried out every other day after quick-dissipating optometry, while re-examination after atropine mydriatic optometry needs to be carried out 3 weeks later, which completes the whole process of mydriatic optometry.

Who doesn't need dilated eyeglasses?

As the age increases, the ciliary muscle adjustment ability gradually weakens. Generally, around the age of 45, the ciliary muscle cannot contract forcefully when the human eye is looking at the near distance, resulting in blurred vision when seeing near. This is "presbyopia". Therefore, people over the age of 45 do not need to dilate their pupils when they undergo optometry.

About 1/3 of myopia among young people in my country is caused by incorrect optometry. Mydriatic optometry can remove false myopia and restore the true refractive state of the eyeball. Incorrect optometry will not only cause discomfort such as eye swelling, eye pain, headache, etc., affecting the long-term wearing of glasses, but also "make falsehoods into reality", developing false myopia into true myopia or causing the degree of myopia to progress rapidly, which is far-reaching. Therefore, we must not try to save time and trouble without mydriasis optometry.

glasses,Mydriatic,optometry