Since a long time ago, people have already started wearing eyeglasses. During those days, the technology is not so advance and there is not so many lens options. In the modern day, many types of lenses have been invented to assist people with different vision problems. There are three main types of eyeglasses including single vision, multi focal, and trifocal lenses. Bifocal lenses offer two vision ranges including near and far. The top zone of the lens allows you to see things from distant places while the bottom zone is used to view near things. When you are viewing near objects such as reading or using the computer, you are using the bottom half of the lens.
Trifocal lenses have three zones including near, intermediate and far. The trifocal lens is designed to help you adjust to your lifestyle.
Unlike bifocal or trifocal lens, the user is not limit to view in 2 or 3 distances. Progressive lenses allow the user to view in all distances in all direction. It does not have lines and is quite comfortable. It is suitable for people that are active and frequently multitask.
Reading glasses can be with or without prescription. Prescription reading glasses are just like the standard glasses that are sold at the optical store. It uses a single vision lens and is suitable for people that suffer from presbyopia.
Besides the lens, you must pay attention to the frame. The frame can be made from plastic or metal. Polycarbonate plastic frame tend to be stronger and resistant against heavy impact.
When buying eyeglass frames, make sure you check the composition of the frame material. Many people are allergic to nickel. People with allergy to nickel will suffer from eczema after wearing the nickel frame for a while. Some people have a more serious allergy while others don’t. Nickel allergy can happen to kids at any age. The rashes will become very itchy and sore. If you suffer from nickel allergy, you should avoid frames that are made from nickel. Instead, you should purchase frame that is made from hypoallergenic material. Examples of hypoallergenic materials include titanium, and aluminum. Plastic frames usually won’t cause skin irritation. The majority of the plastic frames are made from propionate, nylon, and zylonite. The nose pad allergy is associated with nose pads of the metal frames. The common materials that the nose pad is made from include silicone, acetate, PVC, and rubber.
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