What difference do mono-focal glasses and multi-focal glasses have?
A mono-focal lens is a lens with one focal point. Usually, the myopic far-sighted presbyopia that we see belongs to mono-focal glasses. There is only one diopter on one lens, and this is the single focal point. Multi-focal glasses are lenses that have multiple focal points, that is, multiple diopters. Both mono-focal glasses and multi-focal glasses are visual correction tools, but mono-focal glasses can meet basic vision needs, like fatigue relief, control of depth of diopters, and focus on different distances such as the need to see far and near.But because there are many different diopters on a multi-focal glasses lens, so the elderly can not only see far after wearing. When they see close distance, they do not need to take off glasses or wear reading glasses. Wearing multi-focal glasses is not easy to fatigue.
GlassesShop
GlassesShop is the U.S. -owned online eyewear retailer. More than 1 million pairs of glasses have been delivered since the site launched in 2004 while providing the highest quality at an affordable price. The site experience is not only friendly but professional and reliable. They can provide wonderful eyewear at an unbeatable low price. They put the visual needs of customers first in a customer-oriented concept. Prescription glasses frames and sunglasses come with a 90-day warranty. Through a comprehensive, centralized international distribution center, the orders are shipped to all parts of the world, and customers are served across the world.
The Advantages of Polycarbonate Glasses
In fact, polycarbonate glasses come with several benefits and this section will show some of them.
First, polycarbonate glasses are safe and are virtually unbreakable. A study found that polycarbonate glasses were more impact-resistance than glasses or other types of plastic lenses.
Second, polycarbonate glasses are thinner than other types of lenses. This feature makes them ideal for people who have strong prescriptions. Lighter and thinner eyeglasses are less likely to slip off your nose and are more comfortable for everyday wear.
Third, extended exposure to UV radiation from the sun can cause damage to your eyes and lead to some eye conditions such as cataracts or macular degeneration. Of course, polycarbonate glasses can block out harmful UV rays from the sun and provide good protection for your eyes.
However, there are some negative voices of polycarbonate lenses.
Clean Glasses Properly
If the glasses are dirty, don't just wipe them with other cloth. If you use some hard cloth to wipe, it is easy to cause scratches in the lens. Generally speaking, the following cleaning methods are all feasible.
1. Use neutral or alkaline cleaning agent. Remember, toothpaste cannot be used as a substitute for the cleaning agent for spectacle lenses. General optical shops also sell lens cleaners in small bottles, which are easy to carry.
2. Go to the optical shop for professional ultrasonic cleaning. General optical shops provide free cleaning services. The ultrasonic cleaning machine can fully clean every gap and groove of the glasses.
3. Rinse the lens with tap water. Hold the frame in one hand and the cleaner in the other hand. Rub it slowly against the lens, and then rinse it off with clean water. Then wipe it with a glasses cloth or let it dry naturally.
In addition to the glasses cannot be cleaned with alcohol, you should also pay attention to their placement for daily maintenance. Try to avoid putting it under high temperature, and avoid oily, smoke, etc. If you don't use them, put them in the glasses case.
Apart from memory metal frames, what other frames are the most durable?
Nylon plastic frames are the most durable frames available. It is hypoallergenic and flexible. But they are easier to break than metal frames, and their overall strength is reduced by sunlight and the aging process. Titanium and titanium alloy metals are used to make some of the most durable frames. Their strength can be compared with that of stainless steel, but titanium frames provide more options than stainless steel in terms of texture, pattern, and color.
Progressive lenses and single vision lenses
Single vision lenses are the most widely used optical lenses and are suitable for the general population.
Progressive lenses are suitable for below people.
① Myopia control lenses for teenagers. Progressive lenses are used to relieve visual fatigue and control the development speed of myopia.
② Anti-fatigue lenses for adults. Progressive lenses are used for teachers, doctors, people who use too much computer at close range to reduce visual fatigue caused by work.
③ Progressive lenses for Middle-aged and elderly people. A pair of glasses for middle-aged and elderly people to easily see near and far.
How to Know If You Need Bifocal Glasses?
As you get older, you will find that is more and more difficult to read or focus on things that are really close up. This is called presbyopia and it is a common eye condition among older people.
How to know if you need bifocal glasses? If you find yourself squinting at the text that once was easy to read or your vision is blurry, you may need to see an eye doctor. In this situation, you may need bifocal glasses to correct your eyes.
If you currently wear glasses but see print more clearly when you remove them, it is a sign that you may need bifocal glasses in the future.
To know if you need bifocal glasses exactly, check your eyes by an optometrist or ophthalmologist.
