Technological generation in myopia control lenses for adolescents
1.0 Progressive Multi-focus
The principle is to achieve near vision relaxation and regulation, while also correcting myopia and addressing any internal oblique eye positions to ensure proper alignment. This approach helps to relax the eyes, reduce fatigue, and slow down the progression of myopia.
2.0 Peripheral Defocus
Using Peripheral vision control technology, it reduces peripheral defocus, correcting central vision acuity while providing clear peripheral images on the front of the peripheral retina. This can effectively inhibit axial elongation in children and slow down the progression of myopia.
3.0 Multi-point Defocus
Using a multi-zone positive optical defocus design and micro-lenses distributed on the lens, light is focused in front of the retina, creating a treatment zone that slows down axial elongation. This effectively achieves the effect of slowing down the progression of myopia and eye axis development.
Myopia Progression Control Lens Design Principle: Defocus Theory
Modern ophthalmology indicates that in the unaccommodated state of the eye, if the image of an object forms behind the retina for an extended period, it can cause axial elongation of the eye, leading to myopia. This phenomenon is common among adolescents.
When using peripheral defocus lenses to correct myopia, images can be focused not only on the central retina but also on the peripheral retina or in front of it. This effectively sends a “stop”signal to the eyeball to control axial elongation, thereby slowing down the progression of myopia.
Common Lens
The image of the central vision of the single-optical lens correction is projected on the retina, but the periphery is projected behind the retina.
Peripheral Defocus Lenses
After corrected myopia, the central vision image and its periphery are projected to the retina, can also release the peripheral retinal imaging differences.
The third-generation myopia control lenses introduces multi-focal defocus technology, significantly enhancing the effectiveness of myopia control. The central area corrects refractive power, while the surrounding area consists of dispersed micro-lenses to form the defocus zone. The defocus zone of the lens continuously provides myopic defocus effectively enhancing myopia control effectiveness.
Using the principle of multi-point defocus eye axis control technology, our myopia control lens is equipped with 1339 micro-lenses arranged in a continuous dot matrix. The diameter of each micro-lens is the same, and the connected parts from a cylinder, which generates stimulation and forms a defocus signal to slow down the growth of the eye axis. They are independent and connected in series to increase the effective defocus area, slow down the growth of the eye axis, and thus slow down the progression of myopia.
According to the field of view of the human eye and the usage scenario, the ray tracing technology is used to capture the trajectory of the eyeball, and a multi-point arrangement scheme is designed. It has 13 rings of composite rings, and the micro-lenses of each ring are connected to each other to form a 360 defocus ring, forming a myopia defocus and high-order aberration correction ring. Double superposition, safe and effective management of myopia development.
Optometric Guidance
For effective myopia control and comfortable wear of the multi-focal myopia management defocus lenses, consider the following refraction criteria:
- Adequate correction with visual acuity not below 1.0(Snellen), maximum lens power:-1000D myopia, -400D astigmatism, combined power of -1000D.
- Pupil dilation and measurement of monocular pupil height and distance(dilated pupils recommended)
- Absence of manifest strabismus, normal binocular fusion, and accommodation function.
Edging Guide
- Assembly center:Align the geometric cross-center of the defocus zone of the lens with the optometrist’s pupil cross-target center(determined through lens processing yellow mark) for alignment.
- Pupil Height: If the difference in pupil height between both eyes is ≤2mm, use the actual pupil height of the dominant eye to determine the geometric cross-center of the lens’s defocus zone. If the difference is ＞2mm, determine the geometric cross-center based on the midline of the pupil heights of both eyes (Best pupil height:frame height÷2+2≤Optimal pupil height ≤frame height ÷2+6).
- Frame Height Requirement: 30mm-38mm, Optimal Frame Width: FPD-PD≤
- Edging: Select the Polycarbonate(PC) processing mode for edging assembly.
Edging Processing—-Recommended geometric center as pupil high point
Similar to all single point lenses, the geometric center of the multi-focal myopia management defocus lenses may not always coincide with the optical center, but the deviation falls within the national standard range.
Edging Processing—-Recommended geometric center as pupil high point
If the pupil height point coincides with the geometric center of the lens:
- When looking at close objects, both eyes can simultaneously enter the defocus zone, resulting in symmetric and aesthetically pleasing appearance.
- If the pupil height point does not coincide with the geometric center of the lens
- When both eye look upwards or downwards simultaneously, they cannot both enter the defocus zone at the same time, causing an imbalance in binocular vision.
- Aesthetically less pleasing.
- Generally, single focal point lenses are not affected by the above issues, so the optical center can be used as a reference.
Wearing Instructions
- Proper Wearing: Ensure the frame is securely in place to prevent slipping or tilting. Wear the glasses correctly, and if necessary, use non-slip nose pads or ear hooks.
- Regular Adjustment: Periodically recheck and adjust the fit to avoid wearing them askew or deformation caused by external forces, which could affect the effectiveness.
- Maintain Proper Posture: Maintain a proper sitting posture while reading, and avoid lowering the head excessively.
