Orthokeratology lenses appeared in the United States in the 1960s and became mature in the 1980s. In 1996, Taiwan first imported the product, and it entered mainland China the following year. It is called OK lens for short because of its pronunciation. After OK lens entered China, it was immediately found by businessmen. A lot of institutions and individuals who do not have the relevant qualifications have flooded into the operation of the OK lens. On July 5, 2001, the State Food and Drug Administration formulated the Regulations on the Supervision and Administration of the Operation, Inspection and Matching of Orthokeratology Lens, which regulated the operating institutions and testing and matching institutions of Orthokeratology lenses. But in China, the rule did not change the course of events.
At present, there are two prescriptions for reading glasses. One is to adjust the power of glasses with clear objects at close range, plus 1/3 of the power for adjustment. The other is to use low power that can see close objects clearly. The practice of many elderly people has proved that the latter one is better between two methods.
Why are rimless glasses so expensive?
Rimless glasses are the design vantage point in the frame of glasses. The structure of rimless glasses requires many higher physical features (flexibility, surface texture, etc.) and machining accuracy than TR, PEI, and other materials. In order to ensure comfortable wear, the common materials are very exquisite. And for processing technology, the frame is the most difficult. It's not just grinding, it's a full polishing, and it's perforating. This is the technical demand and the most time-consuming.
Figure out the categories of driving glasses
Driving glasses are usually divided into daily and night glasses. Daily use refers to the glasses with anti-glare function and darker colors like gray, brown and gray-green, and other colors. Daily lens transmittance is over 8%. Night type usually refers to the glasses that can prevent glare from headlights of opposite vehicles and increase brightness at the same time. That is, it can prevent lights and not block the road, and can brighten and increase the visual scope. Night lenses have a transmittance of more than 75%.
How To Use Contact Lens Correctly?
A periodic review is necessary. In the process of wearing contact lenses, the eyes may change due to the existence of contact lenses. At the same time, in the process of wearing contact lenses, the lens may be polluted, damaged, and have other changes. This is to check regularly to prevent damage to the eyes. Usually, the recommended review period is one week, one month, three months, half a year, and once every half a year after wearing it.
Gunnar Cruz Blue Light Blocking Glasses Kids
They can protect children's vision and reduce eye strain and headaches while watching tablets, computers, TV, and phone screens. GUNNAR is the gaming glasses of choice for boys and girls alike, and it protects against symptoms caused by spending too much time staring at a screen, including migraines, headaches, dry eyes, blurred vision, cataracts, and macular degeneration. GUNNAR manufactures ergonomically designed gaming/computer glasses with lightweight frames.
Blue light in natural light
Blue light is not the unique light emitted by electronic products, but the visible light that exists in natural light, usually with a wavelength of about 400-500nm. The blue light in the entire waveband can be subdivided into two parts. One part will cause optical damage to the retina of the eye and accelerate the oxidative senescence of cells in the macular area of the retina. Usually, the wavelength of this part of blue light is between 415-450nm, and its damage to the eyes is gradually accumulated and formed. There is also a part of blue light that is beneficial to our human body, that is, blue light with a wavelength of about 480nm. It can adjust biological rhythms and is helpful for sleep, mood, and memory. In addition, experiments have confirmed that daily outdoor activities in the sun can effectively prevent the occurrence of myopia, and short-wavelength blue light may play an important role.