How do myopic glasses work?
The formation principle of myopia is that when the light from the outside world enters the eyeball, it is refracted by the eyeball's refractive system and cannot be accurately imprinted on the retina. The image is in front of the retina. If a concave lens is placed in front of the eye before the light enters the eye, it shifts the focus of the myopic eye from a point in front of the retina to the back, so that it lands directly on the surface of the retina. When parallel light passes through a concave lens, it diverges, meaning that it has already diverged once before entering the eye and then is refracted normally by the eye's refractive system. When the light is refracted through the eyeball, the distance of the image will be longer. So the distance of the image will be correspondingly pushed back compared to the non-divergent light. But it will just fall on the retina, and the image will be accurate in the right place.
Advantages of progressive lenses
1. The appearance of the lens is like a single vision lens, and the dividing line of the degree change cannot be seen. Not only is the appearance beautiful, but more importantly, it protects the age privacy of the wearer. There is no need to worry about leaking the age secret due to wearing glasses.(https://www.koalaeye.com/collections/progressive-glasses)
2. Since the change of lens power is gradual, there will be no image jump. It is comfortable to wear and easy to adapt.
3. Because the degree is gradual, the replacement of the adjustment effect is gradually increased according to the shortening of the short distance. There is no adjustment fluctuation, and it is not easy to cause visual fatigue.
4. Clear vision can be obtained at all distances in the visual range. A pair of glasses meet the use of long-distance, near use, and various distances in between. It is especially good for teachers, doctors, music workers, and computer operators because these people not only need to see far and near objects clearly, but most of the time they also need to be able to see objects at intermediate distances such as blackboards, piano scores, and computer screens. This is not possible with lenses other than progressive lenses.
5. At present, both internal and external ophthalmologists agree that young people should wear low-degree convex lenses when reading and writing to reduce near-use adjustment, thereby alleviating or preventing the occurrence and development of myopia. This gives the progressive multifocal lens a new meaning and mission. Physiology found that excessive use of the eyeball adjustment function can form 'accommodative spasm' or pseudo myopia. Continued development can produce longitudinal eye axis elongation and induce 'true myopia' or axial myopia. The external luminosity of the progressive lens can be artificially added to the progressive luminosity. The upper is used for looking far, and the below is used for looking near, which makes the eyeball relax and over-adjust. The ever-changing luminosity of the lens replaces the 'accommodative power' that should have been activated, blocking the vicious circle of adjusting the eye axis elongation, making the eye not easy to fatigue, and slowing the development of myopia.
Disadvantages of Prism Glasses
Although prism glasses are mostly used for correcting binocular vision, they also have some disadvantages which are said by those who have worn them. They said they suffer from some discomforts, such as headaches, pain with eye movement, wandering eyes. Misaligned eyes, nausea, double vision, and more. In most cases, side effects can be corrected with an adjustment to someone’s lens prescription, eyeglasses frames or medication.
At the same time, you need to know that alignment is extremely important when wearing prism lenses. Prism lenses may be not efficient if they are misaligned. But they can be fixed with a professional adjustment. If you are experiencing any problems with new glasses or your old prism lenses stop working, contact your vision optometrist.
What color lenses are good for driving?
The optometrist reminded us that it is not advisable to choose pink, purple, light blue, and other colors with obvious decoration effects for driving sunglasses. These colored glasses basically cannot protect the eyes. In addition, they may change the color and cause chromatic aberration. Generally speaking, you should wear brown and gray glasses when driving. The brown lens can filter out a lot of blue light, which can effectively improve visual contrast and clarity. The gray lens can absorb any color spectrum in a balanced manner and will not produce obvious chromatic aberration after wearing.
Nowadays, the colors of lenses for sunglasses on the market are dazzling. Many people only consider whether they look good when choosing colors, and do not pay attention to the impact of lens colors on vision. When choosing sunglasses, we should not only pay attention to their decoration but also pay attention to their protective function for the eyes. We should avoid using blue lenses when driving because it will make us unable to distinguish the color of the traffic signal lights.
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.
Sports goggles
With the improvement of people's sports concept and sports protection concept, sports goggles are also widely welcomed. Safety glasses are worn during sports must have four major functions, safety (PC lenses), protection (TR-90 frame, soft and flexible), comfortable (non-slip nose pads and foot covers), and beauty (match sports and leisure clothing).
Sports goggles with shatter-resistant plastic lenses and side shields can prevent balls or sand from hitting the eyes. It can be fixed on the head without worrying about falling off during intense movements. The unique design of the rim of the frame makes the glasses very close to the human face and has a proper external isolation effect so that the human eye is not easy to be attacked by bacteria. The special lens has the functions of anti-fog, anti-shock, and ultraviolet rays, which is very suitable for outdoor activities.
TR90 spectacle frame
TR90 is a composite super-elastic resin material first invented by Koreans and used in the manufacture of glasses. Its characteristics are lightweight, excellent flexibility, and slightly lighter than pure titanium. After this material is being made into a finished product, it is non-adjustable. The application is basically injection molding. Koreans are the first to apply to glasses production, which has been popular for a few years, and then popular in the Japanese market. Now it is basically mass-produced in China. The high-end high-quality TR90 spectacle frames are produced in Shenzhen, and the low-end low-quality ones are in Wenzhou because they are much cheaper.
