Regardless of lens material or price, all sunglasses with polarized lenses provide 100 percent UV protection (though polarized sunglasses tend to be more expensive than sunglasses without this extra glare-blocking feature). This means they protect against both UVA and UVB rays. Polarized lenses work by blocking out light waves that are perpendicular to the plane of polarization, allowing only those that are parallel to it through.
There are two types of polarized lenses: linear polarizers and circular polarizers. Linear polarizers are divided into two categories: conventional linear polarizers and advanced linear polarizers. Conventional linear polarizers are less expensive but offer less protection from UVC radiation (the type of ultraviolet radiation that causes skin cancers). Advanced linear polarizers are more expensive but also block some of the visible light that reaches your eyes. This can help reduce eye strain when viewing screens for long periods of time.
Circular polarizers are divided into three categories: color-tinted, clear, and filter tinted (like in photographs). Color-tinted lenses are white on the outside and colored on the inside; they allow only certain colors of light through. Clear lenses are completely transparent; you can see straight through them. Filter-tinted lenses have a colorless film attached to their surface which blocks most of the light that reaches your eyes, but allows certain colors of light through.
Polarized and UV-protected lenses are not the same. As a result, unless otherwise specified, polarized lenses do not provide UV protection. UV protection isn't enough to make sunglasses effective against reflected light and glare. You also need to avoid direct sunlight.
People who wear prescription lenses often worry about how much protection they're getting from the sun. The truth is that they provide exactly the same amount of protection as ordinary sunglasses. Sunglasses block both visible and ultraviolet (UV) light. Glasses with protective filters attached don't allow any light through them, whether it be visible light or UV radiation. These filters can reduce peripheral vision in certain situations.
Protective filters are usually made from plastic or glass materials. They can be color-coordinated with your frame style and come in flat or curved designs. Buyers should be aware that different brands of protective eyewear perform differently. Some block more UV light than others. Ask yourself what qualities you value in sunglasses before you buy them. Do you care most about visibility or UV protection?
If you drive at all, you know how important it is to get proper eye protection. Driving safely requires being able to see clearly in front of you and on either side of the car.
Although polarization has nothing to do with UV light absorption, many polarized lenses now include a UV-blocking material. Consider wrap-around sunglasses that shield UV rays from the sides if you spend a lot of time outside, especially near water. These lenses are usually polarized, which means they will not only protect your eyes from harmful rays but also enhance your view by giving it a clear, bright color.
Polarized lenses work by using an optically active material to create two different surfaces of glass or plastic that are either flat or angled toward opposite ends of the lens. This creates a single surface that is both transparent and opaque at the same time. Since only light particles (photons) have a horizontal component of movement when entering parallel plates of glass, these particles are forced to move perpendicular to their direction of entry. This means that all of the vertical movements (or polarizations) are canceled out by the glass, leaving only the horizontal movement or polarity intact.
This article explains that although UV radiation is unpolarized, it can be split into two types of waves: transverse-electric (TE) and transverse-magnetic (TM). TE waves have a horizontal electric field and TM waves have a horizontal magnetic field. Only the TE wave type can penetrate clear glass, so if you wear clear glasses with a UV filter in them, you're protecting yourself from dangerous UV rays.