What are Prescription Eyeglasses made of?Written by Timothy Gorman
Prescription eyeglasses are manufactured in a variety of materials. The most basic is glass lens. The glass lens is by far best in absorbing ultraviolet light. It comes in several different colors and is, of course, scratch resistant. It is also one of least expensive. The downfall to glass lens is weight of a pair of prescription eyeglasses made of glass. They are also very breakable and have to undergo a heat-treated process to ensure durability.
Another material used to manufacture prescription eyeglasses is High-Index plastic lens. It also absorbs ultra violet light well. This type of lens is much lighter in weight than glass lens; however, they are also very expensive and can be scratched very easily.
Resin Plastic is another type of material used in manufacturing prescription eyeglass lens. They are lightest of all lenses, but do not offer high level of protection against ultra violet light that other lenses offer.
Sunglasses and the real reason we should wear them.Written by Timothy Gorman
Although majority of nations people wear sunglasses for fashion reasons, sunglasses were invented to serve as protection for eyes against UV Rays produced by natural sunlight.
There are three different types of Ultra Violet Radiation. The first is UVC rays. These rays are mostly absorbed by upper atmosphere and show us no reason to be concerned with them. Next are UVA rays. The human eye directly absorbs UVA rays, however, there seems to be little or no evidence that these rays cause any type of eye disorders. The last of ultra Violet Rays is UVB rays and they are most dangerous rays that cause damage to eyes. Studies conducted by Sunglass Association show that people who wear sunglasses on a regular basis, were less likely to have cataracts later on in life. When choosing a pair of sunglasses, make sure that they indicate on them that they protect from ultra violet rays. Sunglasses can provide 100% of Ultra Violet protection that a person needs. If there is any question about level of protection that your sunglasses offer, take them to your optometrist and they can put them on a machine that will tell how much Ultra violet rays can be absorbed from your sunglasses.