Understand the impact of frame selection on the lens
Frame size is an important consideration when using progressive lenses because some progressive lenses work better in frames of different sizes. Since progressive lenses allow you to see at all distances, it's important that the whole range of vision fits within the frame. Therefore, very short lenses and larger lenses are not suitable for progressive lenses.
Difference Between Blue Light Glasses And Regular Glasses
Studies have shown that blue light is present in many light sources in our lives, especially on screens like cell phones, computers, and televisions. The main health effect of blue light sources is the damage to the eyes. Long-term exposure to blue light sources may cause lesions in the eyes. The harm of blue light to human health can be prevented by corresponding new technology products. Among them, the anti-blue lens is one of them. So how to distinguish between blue-light-blocking glasses and ordinary glasses?
The inadequacies of bifocals
The field of vision is smaller than that of the single vision lens, especially for the close view. For example, reading and reading newspapers need to make it coordinated with the head movement, there are optical defects of image jump and image displacement. There is a boundary, and it is easy to be seen that wearing a bifocal lens exposes age. Bifocals clearly demarcate the near and far regions, affecting appearance and vision. And when far view and close view change, the objects will jump. Because most myopic patients have a lag in the adjustment response, wearing bifocal lenses not only does not delay the development of myopia but has side effects. Therefore, bifocals are not suitable for teenagers to control myopia, and only a few special patients need to wear bifocals.
Application of titanium alloy
Titanium alloy is mainly used in aircraft engine compressor parts, followed by rocket, missile, and high-speed aircraft structural parts.By the mid-1960s, titanium and its alloys were already in common industrial use, making electrodes for industrial electrolysis, condensers for power stations, heaters for petroleum refining and seawater desalination, and pollution control devices.Titanium and its alloys have become a kind of corrosion-resistant structural material.In addition, it is used to produce hydrogen storage materials and shape memory alloys.
What is the cheapest way to buy prescription glasses?
The choice of frames is not only good-looking but also has a lot to do with whether the polished glasses can be worn correctly. Therefore, special attention should be paid to the selection of spectacle frames, and the pupil distance and the optical center of the spectacle lens should be placed in a suitable position. It should also match the shape of the face so that the paired glasses are not only beautiful but also comfortable to wear. If you don’t choose a frame according to this, but choose anyone according to the general rules, the pupils will not match the optical center of the glasses, and the deflection center of the glasses will appear, causing the prism effect, which is very harmful to the eyes. How do choose a frame? Glasses are worn on the face after all, and they have a decorative effect, so you still have to see if they fit your face shape. In addition, the weight should be light and the frame size should be appropriate. It is best to measure the interpupillary distance, otherwise, it is easy to cause squint and cross-sight. It is safer for children to choose a plate frame with resin lenses. There is a wide range of options for adults. Glass lenses have higher hardness and are not easy to wear, while resin lenses have lower hardness but lightweight, good clarity, and higher protection against ultraviolet rays. Although crystals are expensive, they have high ultraviolet and infrared transmittance.
Does the phone screen have irregular color bars when wearing polarized lenses?
It is mainly the special properties of the polarizing film. The polarizer is able to see the internal stresses in the plastic, so when we usually look at the edge of the mobile phone screen, it will have a colored stripe or a black piece, which is mainly caused by the uneven edge pressure when the screen is installed. It's mostly a matter of light and shade. Wearing a polarized lens to see the LCD screen a tilt will find that the screen darkens, mainly because the polarizing lens can absorb light in a certain direction. The LCD screen is a one-way light (different from sunlight), so it is absorbed, so it is found to be dark.
How to adapt to progressive lenses?
People who are prone to motion sickness or have inner ear diseases may suffer dizziness, nausea, vomiting, and other symptoms due to their inability to tolerate the slight deformation of the visual objects, so they need to pay more attention when wearing them. For people who have not worn reading glasses before, it is not recommended to wear graded multi-focus glasses directly because their eyes will not be able to adapt quickly.
