Why do we need to dilate mydriasis_What is mydriasis_What is mydriasis about

Many people don't know much about mydriasis. It refers to the use of some drugs to completely paralyze the ciliary muscles of the eyes, causing them to lose their adjustment, so that they can then undergo an eye test. For teenagers, the eyes have a stronger ability to adjust, so generally speaking, this kind of mydriasis is sometimes needed in order to achieve the effect of enhancing refractive power and achieving a good eye test. Let's take a look at this aspect below.

What is mydriasis?

(1) Children under 12 years of age. Because its regulatory effect is very strong, if the pupil is not dilated during eye examination, the error will be very large.

(2) For patients aged 12 to 40 with myopia, hyperopia or astigmatism, in principle, the pupil should be dilated during the first eye examination. During the second eye examination, if the degree does not change much, the original degree can be adjusted based on the small pupil eye examination.

(3) If fundus and refractive media examinations are normal but visual acuity is poor, mydriasis refraction is needed to rule out refractive error.

(4) More complex refractive errors, such as high myopia, high hyperopia or high astigmatism, or myopia or hyperopia combined with astigmatism.

(5) Teenagers have unstable vision, which may be good at one moment and bad at another. They are suspected of having pseudomyopia. Once the pupil of such patients is dilated, the accommodation effect disappears and the pseudomyopia is eliminated.

Pros and Cons

First of all, it eliminates the over-accommodation and spasm of the ciliary muscles of adolescents, which is more accurate than subjective optometry. At the same time, it avoids the pseudomyopia or astigmatism caused by accommodation spasm, and also has a therapeutic effect on pseudomyopia. In addition, for young children or primary school students who cannot cooperate well, dilating the pupils will allow the light to be reflected clearly, making it easier to perform retinal retinoscopy and obtain reliable objective indicators. It is more accurate and reliable than subjective optometry; it is faster and saves time than mydriasis optometry; for the examiner, there is no inconvenience such as photophobia and poor vision after mydriasis. Especially for the elderly and people with glaucoma, it can avoid complications caused by mydriasis.

Mydriasis may cause temporary inconvenience to the person being examined, such as the eyes being afraid of strong light stimulation for a few days, and having trouble seeing close objects clearly, which affects study and work. So some people are unwilling to accept this approach. In addition, this method cannot be used for eyesight testing for people with glaucoma. Performing eye examination under the condition of auto-adjustment is prone to errors and cannot detect pseudomyopia.