First of all, you have to look at your face shape and skin color, and then combine your working environment needs and personal preferences to choose the frame. The corrective glasses should be combined with the test data. Finally, you have full consideration. The single pair has certain characteristics. And the glasses frame has popular fashion characteristics, so the style is always updated.
Evolution of hard coating technology
The first generation of the use of hard coating technology began in the early 1970s, the quartz material is deposited on the surface of a resin lens under vacuum conditions, form a very hard anti-wear film. However, due to the mismatch between the thermal expansion coefficient and the film base material, it is easy to delaminate and crack the film. Instead, it forms the mottle on the surface of the lens, and the effect is not optimal.
The second generation of hard coating technology is the use of the 1980s. The surface of the resin sheet is coated with a material with high hardness and not easy to be brittle and cracked by an immersion process. At this time, anti-reflection coating lenses had appeared and gained the recognition of consumers, but the mismatch between adding hard coating and anti-reflection coating still caused serious lens wear.
The third generation of hard coating technology was developed in the 1990s, mainly in order to solve the problem of wear resistance after coating resin lenses with an anti-reflection film. The hardened material evolved into a polymer organic matrix material.
Fourth-generation coating technology is dominated by silicon atoms, in which the hardened solution contains both organic substrates. It contains inorganic ultrafine particles, including silicon elements, which make the hard coating not only tough but also hard.
5 Signs You Need Reading Glasses
In this section, we will list some signs you need reading glasses.
- You are over 40 years old. Everyone’s eyesight changes at a different rate, but most people develop presbyopia in their 40s. Presbyopia is a condition in which the eye strain to focus on nearby objects, which is different from farsightedness, a condition in which you can see distant objects clearly, but objects nearby may be blurry. Farsightedness is usually present at birth, but presbyopia develops during the aging process.
- If you find that you never seem to have enough light when reading, regardless of the room type or the number of lamps you have turned on, it may be time to get reading glasses. According to a study, a 60-year-old people requires three times as much light as a 20-year old to do the same task.
- If your eyes get tired when reading or working at your computer, you may need reading glasses. Do you find yourself dozing off at your computer, or do your eyelids get heavy when your reading or do detailed work? If so, you may be developing presbyopia, and you may need the reading glasses.
- Another sign you need reading glasses is that you are getting more headaches. Consistently straining your eyes to read or focus on craft could give more headaches. A headache right behind your eyes could be indicative of hyperopia. It is important to remember the 20-20-20 rule: every 20 minutes, look at something at least 20 feet away for 20 seconds. If your headaches persist, you should see an eye doctor and have a check.
- If you see halos, you may need reading glasses. When your lens cannot focus light into your retina, it makes your vision appear blurry. Thus, reading glasses can solve this problem.
Do I need reading glasses? After reading this post, you may have a basic understanding. If you need a pair of reading glasses, try Koalaeye glasses. They are stylish and cheap, and the glasses will be mailed to you with great convenience.
What are TR90 glasses?
TR-90 (Plastic Titanium) is a kind of polymer material with memory. It is the most popular ultra-light material in the world at present. It has the characteristics of super toughness, collision resistance and abrasion resistance, low friction coefficient, and can effectively prevent the damage caused to the eyes and face due to the fracture and friction of the frame during the movement.
Are metal or plastic eyeglass frames better?
Experts agree that many materials of sunglasses will be targeted, with a high focus on the specific combination of materials used. The frame of your glasses depends on whether you want a stylish or mature look. You can wear different glasses for different situations and clothes. Metal sunglasses are suitable for formal situations or mature types of people, and not easy to damage. Plastic sunglasses are usually more diverse, and the design is changeable. They can be used for a variety of sites. They are suitable for each age group and can be selected according to your actual situation.
Can you buy eyeglasses insurance?
If you've recently realized that you need glasses, you know it's time to start budgeting for them. Glasses can cost hundreds of dollars and may need to be updated every year! But don't stress yourself out. There's a product that can help cover your costs. Technically speaking, there is no official eyewear insurance product. But that doesn't mean that there aren't products that can cover glasses. This product is called vision insurance. But don't call it eyeglass insurance.
What characteristics do children's glasses have?
The lens degrees need to change with the degrees of the eye. Because children are still in the process of growth and development, especially preschool children and adolescent children. Preschool is the key period of visual development, and farsightedness is slowly reduced. The eyeball development is close to an adult. Adolescence is the second peak of eyeball development, and myopia is most in this stage and little by little deepens, stopping at the end of adolescence.
