How the lens is made? It is made by optical processing technology. The quality of optical processing technology directly affects the quality of the lens. The optical processing steps include: cutting, rough grinding, fine grinding, polishing, edging, coating, gluing, etc. A complete set of processes. Every step is important. To make the finished product exquisite, you need to be exquisite at every step and minimize the error.

　　The general processing accuracy of the former domestic optical lens: 1. Outer diameter tolerance-about 0.02~0; 2. Center thickness tolerance: about ±0.02; 3. Eccentricity: 2′ Left and right; 4. Aperture: about 3; 5. Partial aperture: about 0.3; 6. Reflectance after antireflection coating: less than 0.5%.

　　 Note: The marking of optical lenses requires strict tolerance analysis. The general processing accuracy given here is for reference only. In addition, it should be noted that the tighter the tolerance label, the greater the processing difficulty, and the higher the scrap rate of the workshop. For the lens that needs to be considered for cost, this is the result of the tolerance analysis and carefully weighed. of.

　　Structural design

　　 1. With reference to the assembly drawing, the modified lens is mainly divided into the front group, the middle group, the front Pressure cap, middle group two, rear group, spacer, lens body, objective lens shell, pressure ring, spring, rear diaphragm and other parts.

　　2. There are 5 lenses in this design. The first lens is fixed in the front group, and the second and third lenses are cemented together and fixed in the middle group. Here, the fourth lens is fixed in the second group, and the fifth lens is fixed in the rear group.

　　 3. The front group, the middle group, the middle group two, the back group, the spacer is placed inside the lens body, and then pressed by the pressure ring, and the lens body The outer side of the lens is screwed with the objective lens case and the front pressure cap. A spring (to protect the sample) is installed between the lens body and the objective lens shell, and the rear aperture is rotated in the objective lens shell.

　　4. Someone must ask: Why fix the lens in the front group, middle group, middle group and back group instead of directly on the mirror optical lens In the body? That’s because the former method can achieve higher coaxial accuracy. It uses an optical central instrument to determine the mechanical axis of the front group (the machining requirements for the front group are very high, requiring 'one size fits all'), and then move Lens, make the optical axis of the lens coaxial with the mechanical axis of the front group, and then dispense, expose and fix.

　　 5. The front group, middle group, rear group and the lens body have a smaller fit gap, the better, the front group, middle group, rear group outer diameter tolerance and mirror The inner diameter tolerance can be marked at about 5um.

　　 6. The gap between the second group and the lens body is about 0.1 to 0.2, the purpose is to leave a margin for adjusting coma.

　　7. The front group, the middle group, the middle group and the rear group, the spacer ring has a thread (shading wire) inside, the purpose is to reduce stray light.

　　Bionic lenses can keep vision permanently at 5.4?

　　 A report recently attracted the attention of many eyeglasses. A Canadian company successfully developed a bionic lens called 'Ocumetic Focusing Lens'. It only needs to be injected into the eye, and after about 10 seconds, the glasses will automatically unfold in the eyeball. The original poor vision can not only be corrected, but also better than 1.0 vision. However, the lens is only suitable for adults over the age of 25. This technology is being approved by the national government and will come out in 2017 as soon as possible.

　　 reported that this kind of bionic lens is actually an artificial lens, and the transplantation method is also very simple, similar to cataract surgery. It only takes about 8 minutes for the patient's vision to be corrected.

　　 'Ocumetics bionic contact lens' is actually folded like a taco, and can be injected into the eye with a syringe filled with saline. After about 10 seconds, the glasses will automatically unfold in the eyeball, and your vision will be corrected immediately. And this is an outpatient operation, no anaesthetic or hospitalization is required at all.

　　 Even more shocking is that after planting an aspheric lens into this lens, people will maintain good vision no matter how people's eyes age with age. In other words, even if you live to be 100 years old, your vision remains unchanged at 5.4.

　　 Expert opinion 'The lens' is good, the film is not good or useless

　　 Then, this is really 'a subversive 'Invention' is still a kind of hype, which was questioned by industry experts from the very beginning.

　Xia Chengzhi, director of the Department of Ophthalmology, Nanjing Hospital of Integrated Traditional Chinese and Western Medicine, said that the “Ocumetic” bionic lenses actually move the glasses from the bridge of the nose to the inside of the eyeballs, which can be called “eyes”. Inner glasses'. For ordinary simple myopia, the general vision tends to be stable in adulthood. After this kind of lens is implanted, it can replace glasses to achieve the purpose of removing the lens. However, it cannot cure all myopia, such as hereditary high myopia. Even in adulthood, myopia will deepen. Even if this kind of bionic lens is implanted, it cannot prevent the further deepening of myopia.