The development of glasses
In 1451, Nicholas of Cusa of Germany invented a lens that was thinner in the middle and thicker at the end to help short-sighted people. In 1727, Edward Scarlett, an English optician, invented modern frames that could be worn over ears and noses. Benjamin Franklin, an American scientist, and philosopher invented bifocals, which divide the lenses into far and near parts. The two lenses are held together by a metal frame. Frame construction has improved over the centuries, and today frames have come in different kinds of styles and designs. Unbreakable lenses were invented in 1955, and in 1971 a new type of lens combining plastic and glass properties was invented.
What is blue light?
To prevent blue light, we must first understand what blue light is. The visible light with a wavelength range of 400-500 nanometers is called blue light. The light sources used in daily LED lighting and display products, including mobile phones, flat panels, and TVs, are mostly LED light sources excited by blue light. However, not all blue light is harmful to the human body. The human eye has an extremely low tolerance to blue light radiation in the 400-440 nanometer range. When the light intensity enters this threshold, photochemical damage is likely to occur. However, blue light radiation in the range of 459-490 nanometers is essential for regulating the human body's circadian rhythm and can affect the secretion of human melatonin, which in turn has an impact on the body's biological clock, alertness, and mood.
Scientifically effective anti-blue light lenses must not only block harmful blue light but also cannot filter beneficial blue light. Most of the ineffective anti-blue light products on the market currently have two types of problems. One is that there is almost no protective effect on the blue light in the vulnerable zone of the human eye. The other is excessive protection, shielding the blue light spectrum in the beneficial band so that the blue light that is beneficial for physiological adjustment cannot enter the human eye. At the same time, the color of the lens is yellow, which is prone to color shift, aggravating visual fatigue, and even inducing the risk of myopia.
1.67 vs 1.74 High Index Lenses: What Are Their Differences?
In this section, we will show you the differences between 1.67 high index lenses and 1.74 high indexes.
- 74 high index lenses are thinner and lighter than 1.67 high index lenses.
- 74 high index lenses are expensive than the 1.67 high index lenses.
- Both 1.67 and 1.74 high index lenses can reduce the eye distortion caused by strong prescriptions, 1.74 high index lenses perform better than the 1.67 high index lenses.
- As for the color of lens, both come in clear, gray-tinted and brown-tinted, but only 1.67 high index lenses come in Transition brown or gray.
- 74 high index lenses are better for those looking for the thinnest lens possible. So, patients with extremely strong prescriptions chooses this.
- 67 high index lenses are better for those looking to save money or those who do not have extremely high prescriptions. They are also the only choice if you are looking to get Transitions.
From the above information, you can find the main differences between these two lenses are price, thickness, weight, color options and general appearance. Most people who choose 1.67 high index lenses generally either do not have an extremely high prescription or are shopping on a budget. 1.74 high index lenses, on the other hand, are the thinnest and lightest plastic lenses currently in existence.
Advantages of Metal Frames
The metal frame of eyeglasses conforms to the use performance of the frame. They need the material to have high fracture strength, enough plasticity, toughness, and good elasticity. And after the disappearance of the external force, they can restore to the original shape. This is the regular demand for the high elasticity of the metal frame. They must be able to withstand the atmosphere and human sweat daily corrosion. Usually, the corrosion resistance of pure titanium eyewear will be better than other eyewear. Some glasses will have a variety of wonderful grinding designs, and the material must have high plasticity.
The frames use the best acetate from the best suppliers in Europe. The factory that produces acetate is located in northern Italy. Although there are many other acetate manufacturers, they are arguably the best at what they do. In that industry, their acetate has been used in optical manufacturing since 1849.
How Long Does It Take to Get Used to New Glasses?
Most people are excited when they get a new pair of glasses for the first time. But sometimes there is an adjustment period before your vision is fully comfortable. So, how long does it take to get used to new glasses?
In most cases, it takes only a few days to adjust to a new pair of glasses. When you are adjusting to your new glasses, you might experience some symptoms such as mild dizziness, blurry vision, or eye strain. This would be a normal situation. These symptoms are common with new glasses and typically last only a few days.
Even though the new glasses come with the same prescription, different frames or lenses can alter your vision until you get used to the new frame style, frame material or lens type.
Besides, other factors will affect the adjustment time, such as the complexity of your prescription, the type of lens, and so on.
How long does it take to adjust to new glasses? It usually takes a few days. However, if you experience eye strain, distorted vision, and especially headaches for a few weeks, you had better contact the eye doctor or the optician. They will check your eyeglass and the prescription.
Superior properties of titanium alloy
The specific strength (strength/density) of titanium alloy is far higher than other metal structural materials, which can produce high unit strength, good rigidity parts.The engine parts, frames, fasteners, and landing gear are all made of titanium.It can still maintain the demanded strength at medium temperature and can work for a long time at 450 ~ 500℃.