Shape memory alloy
It is made up of nickel, titanium, vanadium, and other metals, and has good elasticity. When faced with external force, the temple can bend more than BETA titanium alloy and can be restored to the original state, so it is named shape memory alloy.
Half titanium frame: Usually, it refers to the titanium combination frame, such as metal frame with pure titanium or β titanium conveniently. It can be reversed, and the former is more common.
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.
How to Get Used to Progressive Lenses?
It is common that your vision may change when you are over age 40. You can find it is happening when have to hold your favorite book, the daily newspaper, or a restaurant menu farther away just to read it. This is an eye condition called presbyopia. It is normal and almost all of us get it as we reach middle age.
This eye condition often can be corrected by progressive lenses which allow you to see objects from far to near clearly. With progressive lenses, you do not have to switch your glasses to see far or near objects frequently.
However, since progressive glasses have three different prescriptions in one lens, it may be difficult for some people to adapt to the new ones. So, in this post, we will show you how to get used to progressive lenses.
What factors make you receive glasses on the same day?
Are your lenses anti-glare or anti-scratch? This may extend the time it takes you to buy glasses. Is your prescription complicated? If so, it could mean your lenses take longer to make. Your favorite frames that you tried out at the store are just for display, so you have to order frames for your glasses. If that particular frame style is in small quantities at the factory, your delivery may be delayed. Some optometrist offices and eyewear retailers have in-house optics LABS. These LABS can make some eyeglass lenses in an hour or so. But the power and design of the other lenses needed to be manufactured by an external optics lab, which took more time.
Production technology of progressive lenses
In addition to the evolution in design, the production technology of progressive lenses is also constantly improving: the most representative one is the free-form technology. The emergence of free-form surface technology makes the production more flexible and rapid and can realize a more personalized design. For now, progressive lens design is done on the inside surface of the lens by a computer-controlled lathe, as if a master engraver could carve a piece of stone into a work of art.
The style of prescription glasses
Choose the material, and then choose the style. The width of the appropriate frame should match the distance between the two pupils to ensure that the eye can pass through the optical center when looking at things. Choose the right style according to your face shape. Generally follow the complementarity principle, such as choosing square frames for round faces and round frames for square faces. After choosing the frame, you should try it on for a while to see if the weight is appropriate and the style is suitable.
How to choose frames?
Of course, the best way is to try it on many times. The visual effect is more direct and reliable than trying on. Spend more time and you can find your own style suitable for you.
In addition, where comfort and aesthetics permit, choose the size as large as possible so that the view will be larger. However, there are some optometric parameters that limit the selection of frames. For example, if the pupil distance is very small, choose a size that is too large is not suitable. Try not to choose the product with spray paint on the surface, because durable time is shorter.
You should pay special attention to that TR, plastic steel, stainless steel, wood, β titanium glasses temple may not be adjusted. When trying on, it should be noted that the weight of the lens has not been added to the trying frame, to avoid the problem of discomfort (such as an easy slip of the frame) found after the preparation.