Titanium is currently too expensive to refine.
It is highly demanding in buckling, stamping, cutting, and welding. The extraction of titanium, like that of aluminum before the 19th century, was quite costly and produced in limited quantities, so it was used only in extremely important fields, such as aerospace, electronics, precision instrument manufacturing, and so on.
The purpose of glasses donation activities.
Regular social donation activities should be carried out in a planned way. For the poor in the rural areas of the disaster area and the poor in the urban districts, donations of materials or funds can not only feel the warmth and humanistic care of society in life and material, quickly resuming production and rebuilding homes. It gives them a sense of psychological security and stability, which is more practical than physical help.
Optix 55 day/night driving glasses
These glasses are designed to provide anti-glare and UV protection. They have a flexible plastic lens and frame that can be used over prescription glasses. They use polarized lenses to make the image look sharper. They help reduce glare, reflection, and its negative effects while improving and brightening the visual area.
Disadvantages of polarized sunglasses
Polarized sunglasses have many benefits. However, in some cases, non-polarized lenses are a safer choice. On cloudy days, drivers find that non-polarized sunglasses are better than polarized sunglasses due to the lack of glare and extreme sunlight.
Driving with polarized lenses after snowing can be dangerous for drivers. As the glare of polarized sunglasses is blocked, ice or snow on the road will not be visible. In this case, the advantages of polarized sunglasses will become the disadvantages that may cause accidents.
In addition, when driving along a dark road with few street lights at night, wearing polarized lenses will make it harder to see the road conditions because they dim the available light better than non-polarized glasses. Of course, in low-light conditions, it is best to avoid wearing sunglasses completely while driving.
The most significant disadvantage of polarized sunglasses is that they do not perform well on digital screens and displays. They can cause the images and information on the LCD screen to blur or disappear at certain angles. Don’t wear polarized sunglasses to use these devices while driving.
What are browline frames?
The name browline comes from the design of the frame. The upper part of the frame is thicker than the lower part so that the wearer's natural eyebrow line can be noticed. The top is usually made of acetate or plastic, and the bottom of the lens is wrapped with a thinner wireframe. Later, the browline frames have also been modified to meet the needs of more customers. Some browline frames use nylon wire instead of metal wire in the lower part, while the browline frames with metal wire are more durable and stable. If people with high myopia want to have a pair of half-rim glasses, browline frames are a good choice.
How to know if lens is polarized?
Make use of LCD screens. Point the glasses horizontally at the LCD screen and then rotate them upward by 45 degrees clockwise. If it is a polarized lens, it will show a change in color deepening. If it does not change no matter how you rotate it, it is not a polarized lens. You can borrow another person's polarized lens or have previously worn a known true polarizer, and place it crossover with the new glasses you want to buy. At this time, you should see the object clearly from the crossover part with your eyes. Then cross the glasses vertically and horizontally, and at this point, the opposite object should not be visible from the intersection. If this condition is satisfied, it means that a true polarized lens is being tested.
Design principle of progressive multifocal lens
For the same piece of the lens, the top is used to see far, the bottom is used to see close. The upper and lower degrees are different.
There is not a sudden change in the distance degree fixed above the lens to the near degree fixed below the lens, but a gradual transition between the two through gradual changes in refractive power, which has special benefits over common bifocals or trifocal lenses.
