What is hard coating on lenses?
Lenses are mainly added in two kinds of film: anti-reflection film and hard film (and some manufacturers produce anti-fogging film and mirror film, but not common). The anti-reflective film is mainly by coating the front surface of the lens with multiple layers of transparent materials with different refractive index and thickness to reduce the excess reflected light on the surface of the lens, by using the principle of light interference. The film can be applied to both glass and resin lenses. The way of hard film plating is usually a soaking process. After many times of soaking and cleaning, soaking in an organic solution containing ultrafine silicon element for a certain time, and then keeping it at a certain temperature for 4-5 hours, the fixed polymerization process of the film has been completed. The surface wear resistance of CR-39 coating can be increased by 2-4 pH, which is similar to the hardness of optical glass lenses.
How do I know what size glasses frame I need?
With unified factory product size, why others can wear without problems, but there is a problem when I wear the glasses? There are differences between the contours of each person's face, including factors such as the width of the head, the distance between the ears and the corners of the eyes as the crow flies, the thickness of the bridge of the nose, and so on, which involves ergonomics. But there is one thing we can agree on. When people with the same ear distance wear the same type of glasses, they have different feelings, even if the arm length of the glasses is the same. People with fatter faces will feel uncomfortable. The face will be uncomfortable because the ear distance is the same, but the face width is not the same, resulting in an increased oblique distance of the temple, resulting in a sense of pressure.
It is very simple to solve this problem. You need to look at a variety of parameters in the frame of the glasses, including the total width of the frame, the length of the arm. These parameters will be reflected in a qualified spectacle frame.
Glasses may have different functional priorities.
Children's glasses focus on the treatment of eye disease, adult glasses focus on improving vision. To children with myopia, matching glasses is to improve vision really, eliminate fatigue, coordinate the muscles inside and outside of the eye, and can prevent myopia to deepen. For children, when they suffer from hyperopia, anisometropia, strabismus, amblyopia, and so on, sometimes they wear glasses to treat eye disease. It is the prerequisite for future vision improvement.
How to Choose Glasses for Heart Shaped Face?
Wearing a great pair of glasses can make you look more beautiful and fashionable. You want to find a pair of eyewear to correct your vision. Of course, they should be comfortable to wear.
Everyone has their unique style. So, finding a pair of great sunglasses is not an easy job. So, in this post, we will show you some suggestions to glasses for heart shaped faces.
Before proceeding with how to choose glasses for heart shaped face, you need to know whether you have a shaped face. Heart shaped face has some obvious features, such as a broad forehead; high, prominent cheekbones; a narrow jawline; and an angular chin. So, you can check whether you have these features.
However, if you do not know what face shape you have, you can click here to take a reference and have a check.
After checking the face shape you have, we will show you some glasses for heart shaped face.
GlassesUSA has a wide variety of glasses.
GlassesUSA has a large selection of frames to choose from. Their frames are classified by gender, designer, color, shape, and trend. In addition to sunglasses and sports glasses, there is an area for children's glasses. GlassesUSA has cheap options and expensive frames. To mark the launch of 3D-printed glasses, GlassesUSA is giving consumers the opportunity to design their own frames for an opportunity to win a $300 GlassesUSA gift card.
Blue light in natural light
Blue light is not the unique light emitted by electronic products, but the visible light that exists in natural light, usually with a wavelength of about 400-500nm. The blue light in the entire waveband can be subdivided into two parts. One part will cause optical damage to the retina of the eye and accelerate the oxidative senescence of cells in the macular area of the retina. Usually, the wavelength of this part of blue light is between 415-450nm, and its damage to the eyes is gradually accumulated and formed. There is also a part of blue light that is beneficial to our human body, that is, blue light with a wavelength of about 480nm. It can adjust biological rhythms and is helpful for sleep, mood, and memory. In addition, experiments have confirmed that daily outdoor activities in the sun can effectively prevent the occurrence of myopia, and short-wavelength blue light may play an important role.
Wearing glasses correctly will not get deeper degrees
The development of myopia is not directly related to wearing glasses. Patients with myopia wear suitable glasses and pay attention to eye hygiene, and the degree of myopia will stabilize at a certain level. But if you think that with glasses, everything will be fine. If you don't pay attention to eye hygiene in normal times, if you continue to keep your eyes in a state of fatigue for a long time, it will lead to vision loss and deepening of myopia. In addition, wearing improper glasses such as no optometry or inaccurate optometry, too large power, will increase the burden on the eyes, reduce vision and deepen the power. For some people with high myopia (more than 600 degrees), although they insist on wearing glasses, the degree will still deepen, accompanied by changes in the fundus, which is medically called pathological myopia. This deepening of myopia is related to the degree of myopia and family and has nothing to do with wearing glasses.