The lenses of prescription glasses
Common materials for lenses include glass, resin, and PC. The glass is fragile and heavy, and few people wear it anymore. PC film is tough and not fragile, but it is not resistant to high temperature and the surface is easily scratched. The most common type of lens on the market today is the resin lens, which is light in weight, hard to break, and reasonable in price. At present, it is generally recommended that you choose resin sheets, and it is recommended that people with ultra-high myopia choose glass sheets.
Generally, lenses can be divided into spherical and aspherical surfaces according to different curvature designs. When choosing, refer to the degree of the eye. For people with lower degrees, There are fewer differences between the two shapes. For people with moderate to high myopia, aspherical lenses will have better imaging effects and clearer vision.
When choosing a lens, a parameter that is often mentioned is the refractive index. Common refractive indexes are 1.56, 1.60, 1.67, and 1.74. With the same degree, the higher the refractive index, the thinner the lens.
The taboos of wearing glasses while driving at night
Night driving members should not wear tawny, green, and gray glasses. Tawny glasses can filter out most of the ultraviolet rays, although can make our eyes feel relaxed but easy to make people sleepy. Green glasses will turn red lights into black, directly affecting our judgment of traffic lights, so there is a great safety risk. Grey glasses, due to their low light transmittance, will weaken our line of sight and affect our observation of the road.
Why do blue light glasses turn yellow?
The glasses are used for a long time. Blue lenses are usually light yellow. If the yellow is too deep, the resin lenses will oxidize and become yellow due to the long-wearing time. The lenses need to be replaced in time. Yellowing of the lens is related to the excessive secretion of facial grease, which leads to yellowing of the lens. The most direct way is to replace the lens glass.
Best Frames For Heart-Shaped Faces
The heart-shaped face should be one of the favorite faces of Asians. It is characterized by a wide forehead, prominent cheekbones, and narrow and pointed lower jaw. This face shape is not balanced up and down in appearance, and the upper part is larger and more prominent than the lower part. Need to wear sunglasses with a wider bottom, which can increase the width of the lower half of the face. The lower mirror foot position also helps to improve this effect. Don't pick a special big style, normal size will do. Pilot sunglasses with a more angular top and bottom can be used to balance the roundness of the heart-shaped face and chin, increase the sense of facial lines, and visually make the face fuller. Retro black round sunglasses, coupled with a handsome choker, highlight the full street casual style. The recently popular 'inverted triangle sunglasses' are also very suitable for heart-shaped faces. The raised angle of the frame can correct the facial lines and add some angularity to the face. The inverted triangle sunglasses also have a retro temperament, and it feels that there is a mysterious demeanor hidden.
Thick Geometric Frames
Eyewear fashion has changed and evolved over the years. Big, thick frames that are round, rectangular, or even hexagonal are loved by celebrities and attendants. Depending on your face shape, you can choose one of these bolder combinations to highlight or contrast some of your face's most obvious features. Hollywood has officially adopted chunky glasses as a necessary item.
The anti-reflection principle of the anti-reflection film
Anti-reflection Coating, known as anti-reflection membrane, is called anti-reflection coating in English, or AR membrane for short. The basis of anti-reflection is the wave and interference of light. The principle is: Two light waves with the same amplitude and the same wavelength are superimposed, then the light wave amplitude is enhanced. The two wavelengths and amplitudes are the same, but the superposition of wavelengths with different wave paths (similar to dislocation) cancels each other out. Therefore, the anti-reflection film plated on the surface of the lens uses this principle to make the reflected light generated by the front and rear surfaces of the film layer interfere with each other, thus canceling each other and achieving the effect of reducing reflection.
Regular eye hospital examination
They must go to the formal professional ophthalmology for optometry and glasses. Wearing glasses after they suffer from myopia, is to correct refraction and clear view. Another important role is to prevent the loss of balance between the adjustment and aggregation functions of the eye. Before getting glasses, they need to go to the hospital for pupil dilation. Many parents are afraid that dilating pupil has a bad impact on their children's study, or afraid that dilating agents will affect the health of their children, so they ask their children to choose computer optometry for glasses. Failure to dilate the pupil and optometry will cause harm to the child's eyes.
