The frame size has increased.
The larger the frame is, the more obvious it is now, so the edge glare will be more obvious when the lens is polished. It interferes with the visual effect. The frame height of the new glasses must be much larger than the height of the old glasses. Because when you buy big frame glasses, they must find out the pupil height when matching outfits. When you get glasses fitted at the opticians, the opticians don't measure the pupil height. That is, the balance line of the lens should be properly moved up when the lens is processed. If it is not moved up, it cannot be seen clearly.
Why can't you wear expired contact lenses?
Contact lenses have a throwaway cycle. If the contact lens has been opened, the shelf life of the contact lens is calculated from the day it was opened. Contact lenses have a life cycle. The life cycle is the shelf life of contact lenses. For example, if you wear daily contact lenses, you will have to throw them away. If you wear monthly contact lenses, they will have a shelf life of one month. Even if you wear them only a few times, you will still have to throw them away. The shelf life of contact lenses is calculated from the day the lenses are taken apart, not from the number of days they have been worn.
After the shelf life of contact lenses, there will be some cases like lens aging, hardening, lens discoloration, decreased transparency, lens deformation, thickening, an increase of lens protein, and other precipitates. The microbe is easy to deposit, resulting in poor oxygen permeability. If you continue to wear it, it is easy to cause inflammation of the conjunctiva and corneal hypoxia, and the comfort level will be much worse. It is suggested to analyze the case according to your own care. Once the contact lenses have the above cases, they should be replaced in time.
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 test a blue-light lens?
Blue-light-blocking lenses are now focused on refractive indices of 1.56 and 1.60. If you buy lenses that are not of either refractive index, be wary. Of course, with the development of technology, now some brands have produced 1.71 refractive indexes blue-light-blocking lenses, suitable for people with high myopia to wear. The true lens package should at least have the product name, refractive index, dispersion coefficient, transmittance, color, SPH, CYL, and other indicators. These indicators are perfect, can be treated as the reference basis of the formal product. In addition, you can go to a professional optical shop or testing institutions for testing.
How do you clean an eyeglass case?
Sprinkle a little water on the glasses case first, to soften the dirt and dust on it. Brush gently with a soft brush to avoid damaging the glasses case. The inside of the case needs to be cleaned with a brush. Use a rag to wipe the surface of the glasses case for moisture and dirt. Wash it several times with a wet cloth. Use paper towels to dry the surface and interior. And then dry in the sun.
Material selection
General glasses material has plastic and metal two categories. Because the children's glasses degrees change faster, from the economic point of view, choosing plastic material is more affordable. And children love to move, they do not pay much attention to pick up and put on glasses. Choosing metal material is easy to distort, affecting the normal wearing. The material of the lens should be light and thin. The transmittance and refractive index should be high, and it should be wear-resistant and not easy to break.
How to determine whether progressive lenses are worn correctly?
Once your glasses are back from the lab, the optometrist will let you put them on for an audition and make final adjustments to make sure they fit. If the prescription is not in the center of the lens, it will make it difficult for you to see clearly. The key is that the lenses match the wearer's eyes, especially the pupils. Before ordering a new lens, the optometrist takes two measurements: pupil distance and fitting height.
