Views:131 Author:Site Editor Publish Time: 2020-12-16 Origin:Site
Presbyopia is a normal physiological phenomenon, not an eye disease, nor is it only among the elderly. After the age of 40, with the gradual fiber hardening of the human eyes, the ciliary muscles are gradually paralyzed, making the human eye unable to effectively adjust the shape of the eyeball (axial change). Only by adjusting the distance between the eye and the object seen, can you see the nearby objects, which must be moved far to be seen clearly. The state of the eyes at this time is called presbyopia. Reading glasses, also known as reading glasses, are a type of optical products used for people with presbyopia, which include bifocal reading glasses, multifocal reading glasses, sun reading glasses and so on. They are convex lenses. Mainly to meet the needs of people with presbyopia, reading glasses are used to supplement vision for middle-aged and elderly people. Like myopia glasses, they have optical indicators specified in many national standards and some special rules of use. The use of reading glasses plays an indispensable role in improving people's quality of life.
By understanding all lens types, you will find a perfect pair of reading glasses. Based on your specific situation, it is important to determine which lens material and lens type will best suit your unique vision needs.
People who will wear reading glasses when carrying heavy machinery may choose a different lens type than those who work in the office. No matter what occasion you want to use your reading glasses, there will be the type for you.
Although there are several different lens material options for prescription glasses, there are two main options for non-prescription reading glasses: plastic lenses and polycarbonate lenses.
Plastic lenses, also known as acrylic lenses, are the most commonly used lens materials for over-the-counter reading glasses and are known for their high definition. Plastic reading glasses lenses are more affordable and lighter than glass lenses. Glass lenses are now rarely used due to their weight and fragility.
Lightweight and impact-resistant polycarbonate reading glasses lenses are used in safety glasses that have ANSI Z87.1 certification, as well as some reading glasses and frameless reader lenses.
The lenses can be divided into daily general lenses, protective lenses, and multifocal lenses according to the use function. The following is a brief introduction to bifocal reading glasses, full magnifying reading glasses, blue reading glasses, sun reading glasses, polarized reading glasses and highly reading glasses.
The bifocal reading glasses have an unmagnified lens, and the lower part of the lens also contains an insert that you can choose the magnification. This type of lens is best for those who constantly switch their sight from near to distant items.
Fully magnified lenses have the magnification you choose throughout the lens. People who prefer this type of lens usually only like to wear reading glasses when performing tasks.
The reading glasses that block blue light can provide your eyes with the required magnification, allowing you to see the screen clearly, while also preventing digital eye fatigue caused by blue light and glare caused by computer screens.
Reading sunglasses, also known as Sun Readers, are reading glasses with light-colored lenses that provide UVA/UVB protection for your eyes. Reading glasses can provide bifocal or fully magnified lenses, which is ideal for any outdoor activities.
Polarized reading glasses have the additional benefit of polarized lenses, which can reduce the glare of the sun and give you a clear vision. Polarized reading glasses are commonly used sunglasses for those on the water, but it is also a good choice for those who see reflected sunlight back from a solid surface.
Reading magnifications greater than +4.00 are considered as high reading glasses, which are difficult to find in non-prescription reading glasses and can only be found in professional hospitals.