Can men wear clear frame glasses?
Clear frames are suitable for young men and women, handsome, with personalities. But if older people wear it, they will look old. Clear glasses frame is more stylish with personality, and it is very fashionable but not for everyone. Choose this kind of frame, you should consider the age, face shape, and so on. Clear frames are usually more suitable for younger people because they are younger and more handsome.
Why do spectacle lenses fog up?
The fog on the surface of the lens is essentially related to the saturation pressure and water vapor liquefaction. The air is full of water molecules, which are constantly doing irregular movements. When there is no temperature difference, water molecules keep hitting the surface of the lens and will keep bouncing off. The lower the temperature, the slower the speed of movement. Therefore, when water molecules hit the cold lens from the hot air, on the one hand, they move too slowly to fly out in time. On the other hand, because of the relatively low temperature of the lens itself and its vicinity, the water vapor will liquefy. As a result, more and more water will accumulate on the lens and form small droplets, eventually forming a foggy layer. As the lens heats up, the mist evaporates back into the air, and the fog disappears.
What Are High-Index Lenses?
High index lenses are eyeglasses lenses that are designed to be thinner and lighter than regular lenses. High-index lenses have a high refractive index than their conventional counterparts. So, they are generally recommended for people who have significantly high refractive errors and strong prescriptions for nearsightedness, farsightedness or astigmatism.
High-index lenses correct all types of refractive errors. And they are also available as single vision lenses, or a reading prescription that corrects presbyopia, such as in a bifocal or progressive lens.
High-index lens has a higher refractive index and which is ranging from 1.53 to 1.74. A lens with an index of 1.74 could be up to 50 percent thinner than a regular plastic lens with an index of 1.50.
Wooden frames: Wooden frames are one of the hottest new trends that pair perfectly with round face shapes. The natural materials used on these frames give this style an elegant feel.
Wayfarer glasses: As for how to choose glasses for round faces, wayfarer glasses are recommended. These frames will bring a touch of old Hollywood to your look. In addition, their distinctive angles add contrast to your features.
So, from the above information, you can know that round faces glasses come in all sorts of shapes and colors. In addition, you can also try Koalaeye glasses, which are stylish and come in at a cheap price.
How To Choose Better Night Driving Glasses?
Choose and buy glasses to use a special night with anti - strong night driving lens. The demand is to block 80-90% of the strong lights and harmful lights, and at the same time to make the road more clearly. Choose glasses with thicker lenses, they are more durable and protect the eyes of drivers against irritation and accidental breakage. As common sunglasses and color-changing glasses are only suitable for daytime wear, wearing them at night will seriously affect the driver's vision.
Common light yellow night driving glasses can only block a small amount of light, and is not very suitable for night driving glasses standards. Therefore, in the choice of lenses of night driving glasses, we must do the selection and demonstration of the national authority of the formal institutions to test products, to achieve the desired effect in actual use. Don't buy products that are not up to standards from vendors. Such products not only do not block the lights but may affect the driver to see the road ahead, affecting the safety of the train operation.
Parameters of lens material selection
Abbe number
Since the refractive index of the lens material varies for the light of different wavelengths, and white light is made up of various colors of light of different wavelengths, the dispersion phenomenon occurs when the lens refracts white light. The dispersion coefficient is an important index to identify the sharpness of lens imaging, which is usually indicated by Abbe number (Abbe number = dispersion coefficient). The larger the Abbe number, the smaller the dispersion, and vice versa, the smaller the Abbe number, the larger the dispersion, and the worse the resolution of the image.
Impact resistance
Humans have been using glass lenses for about 300 years, and it was not until 1947 that the first resin lenses made of CR39 were produced. A big reason for using resin lenses is their safety, i.e. impact resistance. Only lenses that pass the Drop Ball Test are considered safe. Combining the above two parameters, we can compare different lenses.
Do blue light glasses really protect your eyes?
Scientists at the University of Kansas in the United States summarized the results of studies around the world in the past 30 years and pointed out that there is not enough evidence in human trials to prove that blue light is related to macular degeneration, and there is no test showing that blocking blue light glasses are related to macular degeneration. Moreover, experts from the University of S?o Paulo in Brazil have observed after five years that patients who use anti-blue light intraocular lenses after cataract surgery have no difference in the incidence of macular disease compared with those who use ordinary intraocular lenses.
