What Are the Advantages of Progressive Lenses?
We have shown what the progressive lenses are in the above part. Do you know what the advantages of progressive lenses are？.
1. Only need a pair of eyeglasses. As mentioned in the above section, with progressive lenses, you just need a pair of eyeglasses and there is no need for you to change different glasses constantly.
2. No unsightly bifocal line. Progressive lenses come with the multifocal lens without a multifocal line. And there is a smooth shift in lens strength, you don’t have to deal with any sudden changes in clarity.
3. More comfortable. Due to no visible line, you might feel more comfortable with a progressive lens.
Choose a good merchant.
The best option is to return the goods with a quality guarantee.High-quality pure titanium frame production cost is not less than 100 yuan, and online sales will be not less than 50%, so you have to be careful with prices less than 200 yuan. Because pure titanium frame material cost determines its price, the ultra-low price of pure titanium frame is definitely not real.
Orthokeratology lenses are used for myopia control.
The effect of the orthokeratology lens in controlling the increase of myopia in teenagers has been unanimously affirmed by the ophthalmology industry at home and abroad. In February 2006, an authoritative ophthalmological journal published a review of the retarding effect of rigidity breathable orthokeratology lens on the progression of myopia in children. This paper reviews the literature on orthokeratology and myopia in the past 30 years and points out that rigidity breathable orthokeratology can prevent or alleviate the progress of myopia, the mechanism of which is that rigid breathable contact lens can inhibit the progress of myopia by providing clearer retinal image quality. Medium and high concentration of atropine will affect students' near-use vision, while low concentration of atropine has not been used clinically in China, so orthokeratology lens has become one of the known myopia control methods with the best statistical effect. In three to five-year case studies, orthokeratology lenses alleviate a 40 to 60 percent increase in myopia compared with wearing a frame lens or a soft contact lens. Other studies have found that 65 to 70 percent of orthokeratology lens wearers show little or no axial length increase.
WARBY PARKER, one of the most popular eyewear brands in the United States, set up its own experience store in New York City in 2014, where consumers can walk in and out and try them on. They founded a rebellious spirit and lofty goals: to create high-quality, classic production, and the pursuit of fashion and high-quality glasses. Warby Parker's overall design is minimal. They provide many services to help you choose the frame. Almost every frame has a try-on picture and full view and provides a virtual try-on service. Free trial at home, physical experience stores, online virtual tries, and unconditional returns within 30 days really make you feel free.
Tortoiseshell frame glasses can be said to break connotation completely, and this is a very stylish and slightly exaggerated style. It is recommended that fair-skinned, trendy hairstyle and stylish clothes should be worn by boys. After all, if you want to wear stylish tortoiseshell frame glasses, you need clothes and hairstyles to complement them. And if only wear the tortoiseshell frame glasses may not look good.
Parameters of lens material selection
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.
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.
With the improvement of people's sports concept and sports protection concept, sports goggles are also widely welcomed. Safety glasses are worn during sports must have four major functions, safety (PC lenses), protection (TR-90 frame, soft and flexible), comfortable (non-slip nose pads and foot covers), and beauty (match sports and leisure clothing).
Sports goggles with shatter-resistant plastic lenses and side shields can prevent balls or sand from hitting the eyes. It can be fixed on the head without worrying about falling off during intense movements. The unique design of the rim of the frame makes the glasses very close to the human face and has a proper external isolation effect so that the human eye is not easy to be attacked by bacteria. The special lens has the functions of anti-fog, anti-shock, and ultraviolet rays, which is very suitable for outdoor activities.