In the field of myopia prevention and control, OK lenses and defocus frame lenses are currently the mainstream choices. However, due to certain restrictions on the fitting of OK lenses, some families with myopic children cannot choose this method. However, the control effect of the defocused frame mirror tends to be close to that of the OK lens, which is sought after by more and more families, and has won the reputation of "OK mirror on the bridge of the nose". So what is a defocus frame mirror?Can my baby be fitted?In this issue, the German small order is ** point01 What is defocus?Anyone who has taken ** knows that only when the focus is aligned, the image will be clear. We also have one in our eyesSophisticated "camera".The cornea and lens are the lenses, and the retina is the negative of the camera. When parallel light enters the eye, the focus falls on the retina, and we can see clear objects, which can be understood"Spotlight".
Myopic eye:The refractive power is relatively strong, or the eye axis is relatively long, and the light rays converge in front of the retina for imaging, which can be understoodMyopic defocus
Farsightedness:The refractive power is relatively weak, or the eye axis is relatively short, and the light rays converge behind the retina for imaging, which can be understoodHyperopic defocus
Both of these conditions are "out of focus", and whether the light falls in front of or behind the retina, it will cause poor vision.
02 Defocal Frame Lenses vs. Ordinary Single Vision Glasses
The glasses we usually wear belong to the category of ordinary lenses, traditionalSingle vision lenses have only one luminosityObjects seen through the lens can be clearly imaged on the retina, and the vision is very clear.
However, the light passing through the periphery of the lens does not focus on the retina, but instead images behind the retina, causing the eye to receive a signal that continues to grow backwardsPeripheral hyperopic defocusOver time,The eye axis gradually lengthens, and the degree of myopia gradually deepens ......
Therefore, the bigwigs in the ophthalmology field began to study. Now that we already know that defocus around the retina can lead to elongation of the eyeballSo if we can adjust the focus a little closer, can we improve our vision?
As a result, the emergence of defocal lenses just happened to solve this defect of ordinary eyeglasses!
03 Why can defocus lenses control myopia?
It's one of a kindPeripheral myopia defocus principleThe frame lens adopts a special optical design, which not only projects the image at the center of vision onto the retina, but also projects its periphery onto the retina or in front of itPeripheral myopic defocus, which has a great delaying effect on the development of myopia.
Schematic reference diagram of the defocus frame mirror).
In this way, farsighted out-of-focus can be effectively avoided. Give the eyeball a signal to "stop growing backwards", and if the eyeball does not continue to elongate, it will naturally control the progression of myopia and reduce the growth of the eye axis. Studies have shown that:It is currently one of the clinically proven effective means to control the progression of myopia
It should be noted thatThe fitting of defocused lenses has high requirements for the accuracy of the glasses parameters, and each child's eye shape is different, and the personalized customization is very strong, requiring a series of professional and detailed ophthalmology and optometry examinations, and the processing requirements for the lenses are also very strictTherefore, the first step in fitting defocus lenses is to go to a regular ophthalmic medical institution.
04 Who can be fitted?
1.Myopia 1000 degreesBelow,Astigmatism 400 degreesBelow,
2.Not suitable or unwilling to wear OK glassessuch as people under the age of 8 and myopia above 600 degrees;
Vision deepens too quicklyChildren and adolescents(Myopia growth 0.)75d years);
4.Pathological myopia in adults, or friends whose myopia continues to increase in adulthood.
Strabismus, binocular vision dysfunction, anisometropia, and high expectations should all be considered.
05 Comparison of OK mirror and defocus frame mirror
Compared to OK lenses, defocus frame lenses have a wider range of people and do not require cumbersome care steps. In terms of myopia prevention and control, defocus frame lenses are second only to OK lenses, and can make up for the shortcomings of OK lenses in many aspects. Whether it's an OK mirror or an out-of-focus frame lens,The examination and evaluation before the glasses, the adjustment of the fitting parameters, and the regular inspection after the glasses are very strictIn order to ensure the effectiveness and safety of children's wearing.
06 How to make the most of it?
Although the defocus frame lens has a certain effect on the prevention and control of myopia, which can make the children's eyes rise more slowly, there is no guarantee that the power will not rise at all during the wearing process. The following points need to be paid attention to in daily wearing:
Wear it throughout the day:It needs to be worn around the clock, and it cannot be worn when you are lazy or not worn from time to time, and it must be worn every dayMore than 12 hours。In addition to being temporarily removed during bathing, exercising, and sleeping, the longer you wear it, the better the effect of preventing and controlling myopia.
Pay attention to the correct removalHold the temples with both hands, parallel to the cheeks, and align them at the height of the pupils. It cannot be worn with one hand, which can upset the balance of the frame and may even lead to deformationEyes are required during wearingAlign the optical center of the defocused spectacle lensWearing crooked glasses cannot achieve the desired correction effect.
Follow your doctor's instructions for regular check-upsDuring the child's developmental stage, the prescription changes very rapidly, and the child is often active and active, and it is easy to collide with the glasses or cause deformation. With a close review, yesMonitor your child's vision changes at all timessituation, and as neededAdjust the myopia prevention and control planto control the rate of myopia progression to the greatest extent and maintain an ideal state.
Develop good eye habits:Myopia prevention and control is not just a problem with a pair of glasses. The child's daily behavior habits are also crucial, and parents need to supervise the childSitting, eye habits, eating habits, work and rest time, as well as at least 2 hours of outdoor exercise a day, and rational use of electronic products.
References:
1] Optometry Group of the Ophthalmology Branch of the Chinese Medical Association, Optometry Professional Committee of the Ophthalmology Branch of the Chinese Medical Doctor Association. Expert consensus on the application of eyeglasses related to myopia prevention and control in myopia management (2023)[J].Chinese Journal of Optometry and Visual Science, 2023, 25(11): 801-808
2] Optometry Group of the Ophthalmology Branch of the Chinese Medical Association, Optometry Committee of the Ophthalmology Branch of the Chinese Medical Doctor Association, Optometry Group of the Ophthalmology Committee of the China Association of Non-public Medical Institutions, etc. Myopia Management***2022)[J].Chinese Journal of Optometry and Visual Science, 2022, 24(9): 641-648
3] berntsen da, sinnott lt, mutti do, et al. a randomized trial using progressive addition lenses to evaluate theories of myopia progression in children with a high lag of accommodation. invest ophthalmol vis sci, 2012, 53(2): 640-649.