Choosing the Right Glasses to Control Myopia

Nowadays, children explore the world in increasingly diverse ways, with picture books, computers, tablets... leading to high intensity of eye use, making them prone to myopia. According to data from the National Disease Control and Prevention Bureau in 2022, the myopia rate among children and adolescents in China is 51.9%. Although myopia is irreversible, there are still many ways to help children see clearly and even slow down the progression of myopia.

However, when parents discover that their child is myopic, many have questions such as: Will wearing glasses lead to vision dependency? How to control the increase in diopters? Besides reducing electronic products, what else can be done? Before answering these questions, we must first understand the physiological structure of a child's eye.

When a child is born, the eyeball is in a hyperopic state, which is physiological hyperopia, also known as "hyperopic reserve." As age increases, the axial length of the eye changes, and the hyperopic reserve also changes.

According to the "Expert Consensus on Reference Intervals for Hyperopic Reserve, Axial Length, Corneal Curvature, and Related Genetic Factors in Chinese School-Aged Children (2022)": The average hyperopic reserve for 6-year-old children is 1.38 D, and subsequently, the hyperopic reserve decreases at an average rate of 0.14-0.15 D per year, entering the refractive range of emmetropia (0.50 D) at age 12. (Note: D refers to Diopter; "D" preceded by a plus sign (+) indicates hyperopia, for example, +2.50D indicates hyperopia of 250 degrees; "D" preceded by a minus sign (-) indicates myopia, for example, -2.00D indicates myopia of 200 degrees.)

Recommended hyperopia reserve values after cycloplegia in children and adolescents

As age increases, the child's axial length will also grow to a normal length, changing from hyperopia to "hyperopia disappearing." After the axial length grows to a normal length, further growth can easily lead to myopia.

Studies have shown that axial length growth is more pronounced in myopic children between 3 years before the onset of myopia and 5 years after the onset of myopia, and the axial length grows fastest in the year before the onset of myopia. If you don't want your child's myopia to continue to worsen, you need to control the growth of the axial length.

There are some lenses on the market that use specially designed spectacle frames, such as defocus design lenses. Compared with ordinary lenses, these lenses can delay the growth of axial length.

First of all, I want to tell you that wearing single vision lenses is better than not wearing glasses, and wearing defocus lenses is better than wearing ordinary single vision lenses. The principle of defocus lenses comes from the competitive defocus theory. When a child looks at near objects or for too long, the focal point falls behind the retina, forming "hyperopic defocus" that promotes myopia, generating a signal to slow down axial length growth, thereby achieving the effect of slowing down the development of myopia. Defocus lenses designed based on this principle can generate special optical signals in the peripheral area while maintaining clear central power, thereby forming myopic defocus signals and achieving the effect of slowing down the development of myopia.

Studies have shown that lenses using related technical principles have good performance in myopia control. Compared with ordinary single vision products, the axial length growth reduction rate reaches 51% to 62%.

However, after fitting children with defocus lenses, it is still necessary to maintain good eye habits, increase outdoor activity time, and establish a complete refractive development record to delay the increase in myopia better.

Myopia is irreversible, especially for families with myopic children who are in the stage of growth and development, parents should do a good job in the management after myopia. Choosing a professional brand and fitting glasses suitable for children can slow down the increase in their degree, so that they can better explore the world.